This is the first picture of the fresh-faced policeman who gunned down seven teenagers at a late-night house party in a brutal act apparently motivated by revenge. Sheriff’s deputy Tyler Peterson, 20, “went berserk” after an argument with his girlfriend, according to reports.

Fuelled by anger, he burst into her house in Crandon, Wisconsin, where up to ten teenagers all aged 14 to 20 were enjoying pizza and movies, and opened fire.

Today, six people had been confirmed dead, with one fatality believed to be Peterson’s girlfriend, while a seventh was fighting for his life in hospital.

The , who had been at the same school as some of his victims, was eventually brought down by a police sniper after a manhunt.

As news of the shooting filtered through Crandon, which only has 2,000 residents, the community was in shock.

So far, the identity of only one of the dead has been confirmed - 14-year-old Lindsey Stahl.

Armed response: A SWAT team member in action

Her distraught mother Jenny, 39, described how her daughter how phoned her on Saturday night and asked if she could stay at a friend’s.

Tragically, her mother agreed.

“I’m waiting for somebody to wake me up right now. This is a bad, bad dream,” she said, sobbing.

“All I heard, it was a jealous boyfriend and he went berserk. He took them all out.”

Peterson had apparently only been in his job for a week but was not on duty at the time of the shooting.

Crandon police chief John Dennee refused to confirm reports that Peterson was a member of the force’s heavily-armed SWAT team.

Describing the bloodbath, neighbour Marci Franz told how he heard shots from the party early on Sunday morning.

He said: “They sounded distant at first and I was wondering if they were gunshots.

“Then I heard another succession of shots and it sounded very close to my house. Then immediately there was the sound of squealing tyres.”

Source: DM

Filed under: Crandon, Shooting, Wisconsin, gunman, gunshot, policeman, revenge