KGVO News received word from KHQ-TV News in Spokane on Thursday night that an arrest has been made in the brutal slaying of Robert Tester, the nephew of Montana Senator Jon Tester.

22 year-old John Radavich was arrested earlier on Thursday and will be charged with first degree murder for the slashing death of Robert Tester in his home on September 6, 2016.

KHQ Television reporter Hayley Gunther  said court documents indicate that the slain man’s eight year-old daughter told the Spokane County Sheriff’s Department that a man came into their home and awakened them. The assailant was armed with a sword and a knife. Deputies reportedly found Tester’s body in a pool of blood with an ax nearby. Deputies said there was blood on the walls and floors throughout the home.

The child’s grandmother, the victim’s mother, responded to a call from the child, entered the home and discovered the grisly crime scene.

“The homicide scene truly was horrific,” Gunther said. “The victim, 35 year-old Bob Tester’s eight year-old daughter was home at the time of this brutal homicide. The killer approached her and told her to stay in bed because he told her ‘he was going to kill her dad.’

KHQ-TV reports that Tester had a 17 year-old girlfriend that he had allegedly assaulted, and Radavich, the girl's ex-boyfriend, retaliated the next day by killing Tester.

Detective Mark Gregory with the Spokane Valley Sheriff's Office said on Thursday evening that Radavich was contacted at an apartment complex in Spokane Valley, and with assistance from the U.S. Marshall's Service, took Radavich into custody.