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CHICAGO - An off-duty sheriff's deputy who shot and killed six young people in Wisconsin before he was killed acted alone and for reasons that are still not clear, officials have said.
The family of Tyler Peterson, 20, said they were in "shock and disbelief" after hearing that
Peterson had taken the lives of a group of young school friends and former classmates gathered for an autumn reunion.
"We are very sorry for what has happened," Peterson's family said in a statement read by a local pastor at a news conference in the small town of Crandon.
"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. We are struggling to respond."
Investigators said Peterson had killed the victims with an AR-15, an assault rifle also used by local law enforcement agencies.
He was employed by both the Crandon Police Department and the Forest County Sheriff's Department.
At the news conference, Wisconsin Attorney General JB Van Hollen said that "all evidence, from multiple sources, indicates that the perpetrator of these vicious multiple homicides was Tyler Peterson and only Tyler Peterson."
Van Hollen said the evidence included phone conversations Peterson had with local officials after the shootings in which he acknowledged he was the shooter.
Van Hollen said Peterson had arrived at a party shortly before 3am on Sunday. An argument ensued and Peterson went out to his truck, retrieved a rifle, forcibly entered the apartment and opened fire on seven people, killing six of them, including a former girlfriend and five friends.
What the dispute was or why it turned violent was not yet known, he said.
The Milwaukee Journal Sentinel reported that Peterson went to his ex-girlfriend's house hoping to patch up their relationship, but instead got in a fight with her. When other people at the house started calling him a "worthless pig" he lost control, the paper said on its website on Monday.
Five of the victims ranged in age from 14 to 20, and the age of the sixth was not available, according to published reports.
The seventh victim was upgraded from critical to serious condition on Monday. Van Hollen said he had been interviewed by the Wisconsin Department of Justice.
Van Hollen said Peterson also opened fire on a law enforcement colleague who responded to the incident, causing minor injuries to the responding officer.
Peterson fled the scene but was tracked down hours later at a home in a nearby town. Negotiators tried to talk him into surrendering but were unsuccessful. Peterson was then fatally shot, though officials said they did not yet know whether he was killed by a police sniper or took his own life.
Crandon, a town of about 2000 people, is about 290km north of Milwaukee.
- REUTERS