Shooter dead along with six victims in rampage
Shootings happened at about 2:45 a.m. Sunday
Crandon is about 225 miles north of Milwaukee
(CNN) -- A sheriff's deputy shot and killed six people in Crandon, Wisconsin, early Sunday before dying himself under circumstances that remain under wraps, the town's police chief said.
Tyler Peterson, a sheriff's deputy, shot and killed six people, police said.
1 of 3 The assailant, Tyler Peterson, also worked part-time as a Crandon police officer.
Forest County Sheriff Keith Van Cleve said Peterson was "about 20" and was not on duty at the time of the shootings.
Schools superintendent Richard Peters told The Associated Press that three Crandon High students were killed and another three who died had graduated within the past year.
The victims were at a house party together. Residents say one of those killed is or was the shooter's girlfriend.
A survivor of the shooting was in critical condition Sunday night, and a Crandon police officer was treated for minor injuries, according to AP.