Forensic diving: the latest in underwater investigation.

Picture yourself blind, deep underwater, weighted down with 50 pounds of equipment...Unseen dangers lie everywhere, waiting to entangle you: tree limbs, fishing lines, barbed wire, and sharp steel support bars jutting from eroded concrete bridges....You're a detective and this is your crime scene. In this dark, forbidding world, you must collect evidence, take measurements...and document it all with the same accuracy as an investigator on dry land.(1)

Plane crashes, submerged vehicles, boating accidents, suicides, criminal homicide, swimming fatalities, ice rescues, and lost, damaged, or stolen evidence recovery represent just a few of the incidents forensic divers encounter. These underwater investigative specialists face a number of dangers. from underwater hazards to critical incident stress, but emerge from each case better prepared for the next. Agencies that recognize the unique needs of forensic diving teams can properly equip, train, and assist them in their public safety missions.

ENVIRONMENTAL AND PERSONAL RISKS

Environmental factors often create personal risks for divers. These include underwater piping; debris; silt; water depth, current, and temperature; and contaminants. Pollution from lumber, oil, paper, and plastics; medical waste; and organic hazards from both people and animals also pose a threat to divers. NYPD divers once recovered a human corpse in a Bronx sewage treatment plant.(2)

Divers need not enter sewage systems to experience their effects. Sewers often overflow during heavy rains, allowing unfiltered waste to enter the waterways. Exposed to the bacteria, underwater investigators can contract exotic amoebas and parasites, which often lodge in the intestine. If left untreated, these parasites migrate to the liver, eventually destroying it.(3)

In addition to sewage, underwater cables for power and telephones, pipelines for oil and gas, and other debris make locating evidence difficult and place divers at risk.(4) Divers have become snagged on wires, tree branches, fishing line, rope, and boat propellers.(5) One diver got tangled on rope during an underwater training exercise. As he reached down to free himself, some fishing line got caught on his regulator and pulled it from his mouth. Though only a foot below the surface, he had to be rescued by his colleagues.(6)

Even during ideal underwater rescue and recovery operations, visibility often is poor. Underwater sediment, or silt, can create visibility problems for divers. Just as a blizzard can cause a "whiteout," stirred-up sediment can create a "silt-out,"decreasing visibility to near zero and hampering investigations.(7) In fact, forensic divers often conduct investigations using only their sense of touch to recover bodies, personal items, or other important evidence. In one case, a rescue dive team responded to reports of a hand protruding from the silt of a California lake, only to discover that the hand was, in reality, a stick.(8) In another incident, two divers .performing an underwater cave rescue in Venezuela became lost and then separated from each other in the zero-visibility water. One eventually surfaced to freedom, while his partner remained lost. After a 36-hour ordeal, the missing diver was located, dazed but alive.(9)

Forensic diving becomes additionally problematic because water depths and currents can be deceiving. What appears to be calm, shallow water on the surface may actually have deep, swift currents underneath. Some rivers are controlled by dams that may have to be closed to prevent swift currents from interfering with rescue operations. Rescuers may need to drain ponds to provide safety for rescue personnel and assist in recovery efforts, as was the case during a search for a missing Virginia toddler, who was later discovered dead in a river near her home.(10)

Nitrogen poisoning presents another risk for divers who conduct frequent deep-water operations.(11) When divers surface quickly, nitrogen that has pooled in the blood bubbles out, causing decompression sickness,(12) or "the bends." Symptoms include joint pain, back or abdominal pain, paralysis, numbness, tingling, inability to control bowels or urine, headache, dizziness, partial blindness, confusion, shortness of breath, chest pains, coughing and/or shock.(13)

Cold-water rescues pose unique dangers for divers. Equipment may malfunction (regulators can freeze)(14) or be lost in cold water. The potential for disaster is magnified during ice rescues when the diver easily could become the victim. For instance, in 1993, three people died while snowmobiling on a lake in Midland County, Michigan. Rescue personnel arrived on the scene and used their own snowmobile to travel to one of the victims. The snowmobile crashed through the ice, and the rescue worker fell into the frigid water. Fortunately, it took only 3 to 5 minutes for the rescue worker to climb from the water. In the process, however, he lost his radio, rope, and snowmobile.(15)

Forensic divers may experience additional risks, including hypothermia, hyperthermia, air embolism, and dehydration. Hypothermia occurs when the body loses heat faster than it can produce it.(16) Divers exposed to cold water for prolonged periods are likely to suffer from hypothermia, experiencing fatigue, blurred vision, repressed breathing, and/or a lack of muscle control.(17)

In contrast to hypothermia, hyperthermia is a rise in the body's core temperature due to an inability to remain cool. Divers working in hot water or hot climates with cold water can experience hyperthermia, and dehydration increases susceptibility to the condition. As with hypothermia, hyperthermia can cause extreme fatigue, as well as impaired performance, disorientation, and, if severe, loss of consciousness and cardiac arrest.(18)

Air embolism occurs when the lungs overexpand while breathing compressed air underwater. It often happens when a diver rushes to the surface without exhaling(19) and can occur in water as shallow as 4 feet. Symptoms include headache, confusion, weakness, paralysis, unconsciousness, or neurological disorders.(20)

According to experts, dehydration can significantly affect diving operations. For example, a loss of only 1.5 liters of fluid can reduce endurance by 22 percent and cardiovascular efficiency by 10 percent. Moreover, dehydration can cause a decrease in thermal balance and an increase in decompression sickness.(21)

Proper equipment may reduce the dangers of underwater investigation. In addition to using basic diving equipment, underwater investigators often require specialized gear.

FORENSIC EQUIPMENT

Forensic divers must have the necessary equipment to conduct effective underwater investigations. Their specialized equipment includes suitwear, underwater locating and navigation devices, and transportation.

Suitwear

Suitwear consists of two types: wet and dry. Wet suits represent standard equipment for divers. They are designed to protect divers from some of the hazards of underwater recovery, such as fish hooks and broken bottles.(22) Dry suits, which surround divers with air instead of water, insulate divers from chemical, environmental, and thermal hazards.(23) The added thermal protection they provide makes them especially appropriate for forensic divers investigating in waters below 55 degrees.(24) However, while the layer of air can be beneficial, it also can prove dangerous. As a diver changes depths, the volume of air in the dry suit changes, as well, affecting the diver's buoyancy. Unaccustomed to such changes, inexperienced divers may place themselves in jeopardy.(25) Despite their benefits, dry suits can cost as much as $1,800, making them less attractive for dive teams on limited budgets. By contrast, the cost of a wet suit generally ranges from $200 to $600.(26)

Locating Devices

From locating submarines to finding fish, sonar has proven particularly useful for underwater searches. Forensic divers find sonar particularly useful in deep water; it can help locate the target, as well as identify potential hazards. Unfortunately, sonar may not help divers identify unknown targets.(27)

Still, sonar has proven useful in many underwater investigations. Hampered by deep water, swift currents, and unknown boundaries, forensic experts used sonar to locate and recover bodies and parts of the aircraft following the crash of TWA Flight 800 off Long Island, New York, in 1996.(28)

Transportation

During a search and recovery operation, transportation must not only move rescuers to and from the scene but also aid investigators in their missions. Some missions prove more difficult than others. Ice rescues, for example, require special modes of transportation. Ice rescue boards and sleds provide the rescuer a high degree of floatation while allowing easy transition from water to ice and protecting divers' upper torsos from hypothermia. On the other hand, these devices are difficult to maneuver through heavy snow, difficult to balance in moving or open water, and require a substantial amount of strength to manipulate.(29)

Though they require a major financial investment, hovercrafts and airboats are ideal for high-speed and long-distance responses. They prove particularly useful when investigators must respond to remote areas or cover large bodies of water.(30) Like a Jetski with sonar, sonar jetcrafts are well suited to search missions as long as the water stays calm(.31)

Vans can provide ground transportation to and from the scene, while serving as the command post for the operation. Helicopters also can transport divers and equipment to the scene, search for wanted and missing individuals, and rescue victims. While television and movies make helicopter rescues appear effortless, in reality, they require significant training to achieve without harm to both rescuers and victims. Several people have been injured or killed after falling during a helicopter rescue.(32)

The equipment for a successful underwater investigation is only as good as its operator. The proper equipment, in the hands of qualified diving professionals, is essential for safe, effective, and efficient evidence recovery.

EVIDENCE RECOVERY

The success of any investigation depends on locating, preserving, and maintaining accurate records of evidence, and forensic divers face unique challenges in doing so. In addition to poor visibility; water currents, depth, and temperature; and underwater hazards, bottom suction and object shifting may hinder recovery efforts.

Bottom suction often occurs in waterways containing soft mud bottoms. Raising a heavy object underwater requires greater lifting force than on land. The amount of suction depends upon the size and shape of the object and bottom surface environment. Once the item is free of vacuum suction, the possibility exists that the object may break loose uncontrollably, injuring divers and/or destroying evidence. To minimize these dangers when lifting heavy objects, divers should use "pillow bags" and "lift bags," which, when inflated, help push or pull underwater objects. Overpressurization valves release air from the bags and help control the object's ascent.(33)

Objects underwater can shift, trapping victims, endangering rescuers, or destroying valuable evidence. Shifting often occurs due to strong currents, settling, or manipulation by victims or divers. To minimize this problem, divers should secure the objects properly.(34)

Divers also must secure items of evidence located in the water. To do this, they mark the location with buoys, although this might not be necessary in shallow water. Next, the distance from the buoy to a secure marker, such as a bridge, is measured, and a sketch is made to record this information. Using underwater photographic equipment, the item is recorded. Divers then collect the evidence, being careful not to destroy fingerprints or any other characteristics necessary for later identification. It may be necessary to immerse the object in fresh water to preserve its evidentiary value, particularly if it was recovered from polluted or salt water. At this point, divers should follow dry land evidence collection rules and chain of custody guidelines.(35)

The latest in underwater recovery efforts includes the use of canines. Experts agree that dogs can detect people underwater at depths as great as 150 feet.(36) While they sometimes lead investigators astray, they have proven themselves to be major assets in underwater investigations. For example, when a fisherman's capsized boat and gear were found floating over a mile stretch of water on a lake in northern Minnesota, rescuers marked the search area, a region about 2 miles long and one-half mile wide. Approaching the area by boat with the rescue team, Kodi, a Newfoundland, jumped into the water before they even had reached the search site. Doubting her find, the team searched the marked area instead. A few days later, the victim's body was found where Kodi had first indicated.(37)

Training and practice are crucial for effective canine operations, and handlers should follow certain criteria when training their dogs. These include planning an appropriate search, working downwind, studying wind patterns, recognizing and understanding the dog's body language and limitations, using proper safety practices, eliminating the use of harnesses, and making training fun.(38)

Finding the right dog can help the process. Some agencies prefer Labrador retrievers, while others favor golden retrievers, bloodhounds, or Newfoundlands.(39) Regardless of the breed, the best dogs have an easygoing temperament, possess a healthy prey instinct, swim strongly, and possess a keen interest in their surroundings. They also should be trained as puppies.(40) One handler begins training search dogs at approximately 8 months old. Scent training starts on land and eventually progresses to the water.(41) In short, the qualifications and training for diving dogs are as important as the qualifications and training required for forensic divers.

QUALIFICATIONS AND TRAINING

Qualifications and training for forensic divers vary between agencies. To qualify for one of the Virginia State Police's seven diving teams, candidates must have at least 2 years' experience as troopers and receive written endorsements from their supervisors. They must pass a physical test that includes swimming 800 yards, treading water for 15 minutes, swimming 75 feet underwater without breathing apparatus, running 1.5 miles, and completing a minimum number of push-ups and sit-ups. Following a successful interview, candidates attend a 5-week diving school, often followed by specialized training, and mandatory in-service training.(42) In addition to passing a physical endurance test, candidates for the New York Police Department's dive team must pass a written diving exam.(43)

Qualification and training exercises for diving teams should supplement, not replace, departmental physical and/or psychological requirements. Forensic divers must maintain their fitness and educational standards in order to stay on the team. While these requirements may appear stringent, divers must be prepared to handle the many environmental and personal dangers associated with underwater investigation, as well as the stress that often accompanies the job.

STRESS MANAGEMENT

While many employees experience occupational stress, forensic divers experience unique stressors, including dangerous working conditions; intensive and extensive training; 24-hour availability; high demand for success; and witnessing, preventing, or responding to disasters. As a result, divers and their supervisors should recognize the signs of stress, such as poor eating and sleeping habits, inability to focus, failure to perform duties, argumentativeness, unnecessary risk taking, decreased interaction with team members, increased cynicism, lack of caring, loss of motivation, and emotional exhaustion (burnout). Unmanaged stress can cause high blood pressure, fatigue, eye strain, shallow breathing, headaches, digestive problems, increased use of alcohol and tobacco, and domestic and personal problems. Although stress is an inevitable part of the job, dive team members can take certain steps to reduce it, including maintaining proper eating and rest schedules; participating in a physical fitness program; practicing relaxation methods; and turning to a friend, family member, therapist, clergy member, or other person who can lend a sympathetic ear.(44)

MEDIA RELATIONS

The scene of a critical incident can become a media event, putting additional stress on the dive team. To prevent unnecessary distractions for members of the team, investigators should appoint a media relations liaison. This person can establish a command post to give news people a central location to ask questions and conduct interviews. In addition, the liaison can review news coverage of the event with team members to serve as a teaching tool, indicating how the team can improve not only its relationship with the media operations but its operations, as well.(45)

Inviting the media to dive team training sessions can eliminate the need to explain basic procedures during actual events. Encouraging news stories during down times also would increase public awareness and possibly increase funding for diving operations.(46) In short, the media liaison should work to get the entire community behind the diving team.

TEAMWORK

Underwater investigations require dedicated individuals working as a team to accomplish a common goal. The work can be physically and emotionally demanding and requires strict adherence to many procedures, rules, and standards. Life-and-death decisions must be made in seconds. Team members must be able to meet the demands of the job without complaining or condemning; egos must take a backseat. Uncooperative members complicate the function of the team and place members at risk.

Cooperation includes effective communication. Communication during underwater investigations is hindered by the nature of the operation. Nonverbal communication is the rule rather than the exception. Members often use line signals to communicate. Team members must be able to recognize when other team members are in trouble, whether they signal or not. Communication also can be hampered when volunteers, who do not know the signals, help with a mission.

While the use of volunteers is under debate, the failure to allow volunteers to assist may be grounds for legal action. For example, in Lake County, Illinois, the family of a drowning victim received a $1.3 million out-of-court settlement, after authorities at the scene prevented two civilian scuba divers from rescuing the victim. By the time county rescue divers reached the scene 18 minutes later, it was too late.(47) Still, for both safety reasons and evidence protection, forensic divers must not allow unqualified individuals to enter the scene. Volunteers who are not versed in evidence recovery can destroy valuable evidence.

Unfortunately, some smaller agencies with limited resources need volunteers to augment their recovery operations. Other agencies share dive team members and equipment. While this arrangement may appear cost-effective, difficulties can arise when divers from one region fail to respond to rescue operations, equipment needed for operations is stored in another region, or shared equipment proves incompatible.

A specialized regional diving team could solve these problems. One team could specialize in rescue diving; another team, evidence collection. This would minimize the dangers of mishandled evidence for courtroom presentation, while providing the necessary resources to complete the operation successfully.(48)

CONCLUSION

The underwater world of a forensic diver is fraught with danger. Whether performing a rescue mission or salvaging evidence, law enforcement dive teams brave a myriad of elements to achieve their goals. They do so with a dedication to duty and an esprit de corps that makes so many difficult law enforcement duties possible.

While still in its infancy, forensic diving has made many contributions to law enforcement in search and rescue operations. This trend likely will continue as agencies recognize the value of dive teams, criminals seek alternate means of evidence disposal,(49) and accidents happen. With the right training, equipment, and support, forensic dive teams can take law enforcement operations to previously unattainable depths.

Diver Line Signals

Line Tender to Diver

1 tug: "Are you O.K.?"

2 tugs: "Stop, change direction, take out line"

3 tugs: "Come to surface"

4 tugs: "Stop" (danger on surface or in water)

Diver to Line Tender

1 tug: "O.K."

2 tugs: "Need more line"

3 tugs: "Have located object"

4 tugs: "Need help"

Diver to Diver

1 tug: "O.K."

2 tugs: "Pattern completed, release more line"

3 tugs: "Mission completed - object found"

4 tugs: "Help" or "I need assistance"

Source: Professional Association of Diving Instructors, Underwater Investigator, handout No. 12.

Endnotess

1 R. Foster, "Where Many Fear to Tread Water...," The Roanoke Times, August 19, 1996, A1, A8.

2 M. Kaylan, "N.Y.P.D. Not So Blue," New York, May 15, 1995, 48.

3 Ibid.

4 "On the Waterfront," New York, March 29, 1993, 24.

5 In Foster, A1; and B. Wilson, "Safety Considerations When Diving Under or Near Vessels," Searchlines (1995): 10-11.

6 Editorial, Searchlines (March/April 1992): 7.

7 S.M. Barsky, "Zero Gravity Diving and Proper Trim," Searchlines (September/December 1992): 26-29.

8 J. Morgan, "Copper Canyon Search," Searchlines (1996): 25.

9 S. Gerrard, "Cave Diving Rescue in Venezuela," Searchlines (March/April 1992): 13-16.

10 L. Smith and C.W. Hall, "Body of Missing Toddler Found in River; Probe Continues," The Washington Post, A1, A16.

11 Kaylan, 49.

12 J.K. Jeffries, "Fluid Management and Diving," Searchlines (March/April 1993): 12-13: and Dr. Isaac Van Patten, forensic diver, Roanoke, VA, interview by the author, October 22, 1997.

13 National Oceanic and Atmospheric Administration (NOAA), Emergency Consultation Diving Accidents (handout); and Michael Dunn, "Hyberbaric Oxygen Treatment for Divers, Searchlines (1996): 14-15.

14 D.A. Sommers, "Tittabawassee River Plane Crash," Searchlines (March/April 1992): 4-6.

15 J. Nielsen, "Team Tips," Searchlines (March/April 1993): 18-19.

16 J. Kushner, "Field Recognition and Treatment of Immersion Hypothermia," Searchlines (September/December 1992): 11.

17 V.P. Igoe, "Police Divers Are Agency Asset," Searchlines (1995): 25-26.

18 Jeffries, 13; and Kushner, 11-15.

19 R.G. Teather, The Underwater Investigator (Colorado: Concept Systems Inc., 1983), 45.

20 NOAA, Emergency Consultation Diving Accidents (handout).

21 Jeffries, 12-13.

22 In Foster, A8.

23 Igoe, 26.

24 J. Hardy and B.S. Shuster, "Gear Review: Dry Suits," Searchlines (March/April 1993): 4-8, 16.

25 Igoe, 26.

26 Dr. Isaac Van Patten, forensic diver, Roanoke, Virginia, interview by the author, September 26, 1997.

27 K. Burton, "Sound Navigation and Ranging," Searchlines (September/December 1992): 40-43; and J.W. Will, "Sonar: Underwater Search and Recovery," FBI Law Enforcement Bulletin, May 1987, 1-5.

28 S.F. Kovaleski and D. Phillips, "Proof of Explosive Eludes Probers in TWA Crash, The Washington Post, September 3, 1996, A1, A4.

29 S.J. Linton, "Ice Rescue Equipment for the 90s," Searchlines (September/December 1992): 6-10.

30 Ibid.

31 S.J. Linton, "Sonar Jetcraft," Searchlines (September/December 1992): 47.

32 J.F. Segerstrom, "Helicopters," Searchlines (1996): 16-21.

33 Professional Association of Diving Instructors (PADI), Underwater Investigator Rigging and Light Salvage, (handout No. 13).

34 Ibid.

35 In Foster, A8.

36 In A. Wright, "Boat Collision Devastates Family," The News and Observer, August 10, 1994, 1A, 4A; and R.G. Teather, "Decomposition Gases and the Use of Search Dogs," Searchlines (July/August 1992): 18-19.

37 D. Oehlke, "Lake Region Search and Rescue," Searchlines (July/August 1992): 22-23, 25.

38 M. Hardy, "Training the Water Search Dog Team," Searchlines (July/August 1992): 4-11, 24.

39 G. Haschak, "K-9 to the Rescue," Searchlines (July/August 1992): 12, 15, 17.

40 Oehlke, 22-23, 25.

41 Handler Scott Hansen, in G. Haschak, "K-9 to the Rescue," Searchlines (July/August 1992): 12, 15, 17.

42 Sergeant Mike Berry, coordinator and supervisor, Virginia State Police diving teams, interview by the author, February 18, 1997.

43 Lieutenant Rich Angley, NYPD, in M. Kaylan, "N.Y.P.D. Not So Blue," New York, May 15, 1995, 45-49.

44 T. Burke, "The Relationship Between Dispatcher Stress and Social Support, Job Satisfaction, and Locus of Control, doctoral dissertation, City University of New York, 1991; J. G. Stratton, Police Passages (Manhattan Beach, CA: Glennon Publishing, 1984), 287-318; and R. G. Teather, "Stress and Your Dive Team, Searchlines (1996): 10-13.

45 R.G. Teather, "Performance Anxiety," Searchlines 9, 3, May/June, 1992, 10; and R.G. Teather, "Stress and Your Dive Team, Searchlines (1996): 10-13.

46 D.A. Sommers, "Media Relations," Searchlines (1995): 12-14.

47 P.H. Colby, "Thanks, but No Thanks...," Searchlines (1995): 7-9.

48 Sgt. Curtis Cook, Montgomery County Virginia Sheriff's Department, in K. Loan, "Divers Volunteer for Tough Job," The Roanoke Times, August 15, 1995, (online article), http://scholar4.lib.vt.edu/VA-news/ROA-Times/issues/1995/rt9508/950815/9508150105.html, accessed on August 27, 1996. This site no longer accessible. For the text of this article, visit http://archives.roanoke.com/archives/cgi-bin/siwebcli-post.pl.

49 Igoe, 6.

Dr. Tod W. Burke is an associate professor with the department of criminal justice at Radford University, in Radford, Virginia.

Dr. Charles E. O'Rear is professor and chair of the department of forensic science at George Washington University, in Washington, DC.