The teen accused of killing four of his family members was previously charged with assaulting other close relatives, and now faces another charge of assaulting a jail guard.
Malachi Maxon, 18, was charged with four counts of first-degree murder in the shooting deaths early Monday of his aunt and three cousins aged 18, 10 and 7.
At the time of the shootings, Maxon faced other charges involving alleged assaults on relatives including his mother and stepfather, court documents said.
Maxon is expected to be charged with fourth-degree assault after authorities say he attacked a corrections officer at a pretrial facility in Palmer on Wednesday, authorities said.
Maxon did not immediately enter a plea on the murder charges. An arraignment was delayed after he refused to participate Wednesday and the hearing was rescheduled for Thursday.
An email sent Thursday to the Public Defender Agency in Palmer, which is listed as Maxon’s legal representative, was not immediately returned.
Maxon is accused of first shooting his cousin, 18-year-old Cody Roehl, at a home near Wasilla and stealing a vehicle and a semiautomatic Glock pistol, charging documents said. Roehl was pronounced dead at a nearby hospital.
Maxon then broke into a home in nearby Palmer through a basement window and shot his aunt and two younger cousins, charging documents said.
Police found 43-year-old Kimora Buster dead on the floor. They also found 7-year-old Ellison Buster dead in his bed and 10-year-old Sienna Buster injured in her bed. Sienna later died at a hospital, authorities said.
A 6-year-old, only identified as AB, was found uninjured in the bed with Ellison, charging documents said.
On Wednesday, a corrections officer was recovering from minor injuries after Maxon assaulted the guard when a cell door was opened to deliver a food tray, Alaska State Troopers said.
In July, Maxon was charged with domestic violence assault and interfering with a report of a domestic-violence crime after allegedly attacking his mother at her home in Wasilla, court documents said.
Maxon was charged in October with criminal mischief, domestic violence assault and violating conditions of release for an alleged attack on his stepfather. He was released from custody about three weeks later on $200 bail and ordered to wear an ankle monitor.
Authorities charged Maxon in November with two counts of misdemeanor domestic-violence assault and criminal mischief stemming from a confrontation with his uncle at his grandmother’s home.
None of the domestic violence assault charges have gone to trial.
Maxon was released from custody Nov. 23, a week before the homicides, on $500 cash bail and a $2,500 unsecured bond.