CRANDON, Wisconsin (CNN) — An off-duty sheriff's deputy used a police-style AR-15 rifle to kill six people at an early morning party in a small Wisconsin town, officials said Monday.
Tyler Peterson, 20, shot himself twice under the chin, while the third and fatal shot entered the right side of his head, state attorney General J.B. Van Hollen said.
Twenty-year-old Tyler Peterson had gone to the party early Sunday to make amends with his ex-girlfriend, a friend of Peterson's told The Milwaukee Journal Sentinel.
Peterson lost control after people called him a "worthless pig," Mike Kegley told the paper.
Peterson left and got a police-style AR-15 rifle from his truck, forced his way back into the apartment and fired about 30 rounds at about 2:45 a.m. (3:45 a.m. ET). Six people were killed; one person survived and is hospitalized, Attorney General J.B. Van Hollen said at a Monday news conference.
Peterson was killed in a shootout with law officers Sunday afternoon after negotiations for his surrender failed, officials said. The town's mayor said Tyler was killed by a SWAT team sniper.
The dead and wounded were all students or graduates of Crandon High School, and Peterson was a graduate of the school, which has a little more than 300 students.
Witnesses said the victims ranged in age from 14 to 20, and one was apparently Peterson's former girlfriend.
Peterson's family, in a statement read by Bill Farr, a pastor, expressed condolences to the victim's relatives and said they could not find any reason for the killings.
"We are grieving for your losses. We are very sorry for what has happened. This huge tragedy has deeply affected everyone, including us. We also feel a tremendous amount of guilt and shame for the horrible acts Tyler committed. This is not the Tyler we knew and loved," the statement read.