A-LEVEL GIRL HELD OVER KNIFE DEATH; Teenager in custody after her boyfriend dies from stab wounds.

Byline: Matt Withers, Ben Glaze and Tim Lewis 

A TEENAGER was under arrest last night on suspicion of stabbing her boyfriend to death just hours after collecting her A-level results.

Detectives were last night questioning 18-year-old Kat McGrath at Bridgend Police Station on suspicion of murdering her partner Alyn Thomas, 22.

Emergency services were called to the town's Brackla estate during the early hours of yesterday.

Police are working on the theory that McGrath collected her exam results on Thursday morning from Brynteg Comprehensive School and went drinking with friends to celebrate before later arguing with her boyfriend.

It is understood Mr Thomas, from Cymmer, near Maesteg, turn to page 2 from page 1 was found in a pool of blood with knife wounds at adetached house inFenwick Drive, which is off Brackla Way and backs onto TremainsWood.

The Welsh Ambulance Service said paramedics also attended the property, whereMiss McGrath is believed to live with her dad Martin and mum Carla.

The pair's social networking accounts on the MySpacewebsite describe them as boyfriend and girlfriend and they had been posting heartfelt messages to each other just a few days before the killing.

Alyn Thomas left a note on Wednesday with the words "I LOVE YOU" repeated 12 times on Kat's web page and under the "About Me" section of his own page he had written "I love Kat!" InMay he had also posted "I love Kat" on her site more than 30 times in thesamemessage, whichhadbeensent in the early hours of the morning .

His profile on the Microsoft Live site saidhewas currentlyworking part-time at the Tesco store in Neath having finished college, and that hewas thinking of going back to university.

Helisted his interests as gigs, gaming, tattoos and kick-boxing.

Kat's MySpace page profile lists her interests asmusic, party dressing, reading and acoustic guitar.

According to neighbours, her father was at the family's holiday home in Ireland at the time of the deathandwas last night making his way home by ferry.

Her mother had not gone to Ireland and was still at home last night .

Neighbours in the quiet cul-de-sac of houses have described them as a "lovely" family and said Katwas a very quiet girl whom they rarely saw.

They said people had been walking up the street throughout the day to see what had happened.

There was police tape around the house last night and an officer in a patrol car was due to remain outside the home for the rest of the night.

AtMrThomas'homeinCymeraman whoansweredthe front door confirmed Alynhaddied but declined tocomment any further.

ASouthWalesPolice spokesman said an incident room has been set up at Bridgend Police Station .

White-suited forensic scientists could be seen inFenwickDrive yesterday and inside the house gathering evidence.

Uniformed police officers carried out house-to-house inquiries, asking neighbourswhat they had seen and heard on Thursday night.

The police spokesman added: "The scene has been sealed and a forensic examination is continuing.

"An 18-year-old woman has been arrested on suspicion ofmurder and is in custody .

"Next of kin have been informed and an incident room has been set up at Bridgend Police Station."

Brackla councillorDaveSagesaid last night: "It's a big shock for the community when something like this happens and a tragedy for the victim.

"Our deepest and heartfelt sympathies go to the dead man's family and I urge anyone who knows anything to co-operate with the police."

18-year-old 'had been celebrating her A-level results'

CAPTION(S):

A police officer stands guard outside the house in Fenwick Drive, Brackla, where a man was alleged to have been murdered yesterday