WHAT STARTED KILLER'S FRENZY?

Byline: Josh Kleinbaum, Eric Leach and Jason Kandel Staff Writers

THOUSAND OAKS - When Steve Mazin invited Toby Whelchel into his home five years ago, he thought he had found a golfing buddy and friend as well as a client.

Instead, Whelchel, a former Air Force captain with a history of violent crimes, played a key role in Mazin's crumbling marriage and - for reasons that remain a mystery - exploded into a two-day rampage that left Mazin and two others dead and five people seriously injured.

The spree ended with Whelchel, 38, killing himself in the Simi Valley Wal-Mart store and leaving investigators trying to figure out what set him off.

``When I heard who it was, there was an, `Oh, of course!'' said Fred Sirota, an attorney who worked with Mazin on and off for the past six years.

Whelchel and Mazin first met about five years ago, when Whelchel hired Mazin to represent him in a personal injury case, court records show.

Whelchel quickly joined Mazin's inner circle - which included Tim and Janice Heyne. The Heynes were at Mazin's house Monday during Whelchel's attack. Whelchel killed Mazin and Janice Heyne and injured Tim Heyne.

Mazin and Whelchel had became golfing buddies, and Mazin invited Whelchel to stay at his large home on Calle Laredo in the Lynn Ranch area of Thousand Oaks.

About that time, Whelchel and Mazin's wife, Joanne, began working together on a carnival and party-planning business. Whelchel invented the Water Bomb Battle Zone, a carnival game in which people fire water balloons at each other. The game became the centerpiece booth for Water Bombs, a company owned by Joanne Mazin.

Through the family friendship with the Mazins, Christian Heyne, Tim and Janice's son, ran the Battle Zone booth at occasional local events.

``I thought he was a little eccentric, but who isn't?'' Tim Heyne said. ``It wasn't weird in a scary way, it was weird in a joking way.''

As Whelchel's relationship with Joanne Mazin strengthened, his relationship with Steve Mazin deteriorated. During a meeting at Mazin's Westlake Village office, Whelchel began shouting at the attorney loud enough to be heard through a closed door, Sirota said.

The growing divide between the two culminated in a bloody fight at Mazin's Calle Laredo house. After that, Mazin requested a restraining order to keep Whelchel away from him and his son, calling Whelchel ``dangerous and violent'' in court papers.

Steve and Joanne Mazin, married since 1986, separated in 2002. Steve Mazin moved to a house on Montgomery Road - where Whelchel's two days of terror began. Whelchel's name peppered court documents from the divorce. Steve Mazin accused his wife Joanne and Whelchel of having an affair, an allegation Joanne denied in court papers.

``They weren't romantically involved at all, and they never have been,'' said Joanne's divorce attorney, Hilary Shankin. ``She denied it under penalty of perjury several times.''

Whelchel's violent history dates back 15 years, well before meeting the Mazins. In 1990, he was arrested in Florida for assaulting a police officer and disorderly intoxication. He later joined the Air Force and advanced to the rank of captain, but was discharged in 1999 for a six-month history of showing up late for work, Air Force officials said.

Whelchel lived in Corona briefly in 2000, where he formed a business called JOAD Enterprises, according to county records. He tangled with the authorities in Corona and Santa Rosa, and court records indicate that he responded to police questioning by shouting obscenities and struggling with officers.

By July 2001, Whelchel had moved to Indiana, where he was arrested on felony battery charges, Hamilton County officials said. A summons mailed to his Noblesville, Ind., address in June 2002 was returned to the county. He had moved back to California, where he reunited with the Mazins.

``There was some intangible thing about him,'' Sirota said. ``He seemed slightly uptight. He had the military training. Unfortunately, it seems like he was a pretty good marksman.''

Josh Kleinbaum, [phone]

josh.kleinbaum(at)dailynews.com

CAPTION(S):

3 photos

Photo:

(1 -- 2) A photo of Janice and Tim Heyne is at a small memorial at Steve Mazin's home, where Mazin, above, and Janice Heyne were shot and killed by gunman Toby Whelchel, and Tim Heyne wounded.

Tina Burch/Staff Photographer

(3 -- color) WHELCHEL