Bob Tester, 35, was found lying in a pool of blood in his residence outside the city of Spokane on Tuesday morning, reports KXLY, a local ABC affiliate.
"We do not believe that this was a random act," said Mark Gregory of the Spokane Sheriff's Office. "We do believe that the suspect knew the victim."
Along with the police report, authorities also released the full text of Tester’s last Facebook post.
“There’s gonna be some hard days ahead of us but i want you all to know that I was victimized by someone close to me," the Aug. 25 post reads. "He took my best friend from me and turned her life into darkness, thru drugs and manipulation… Just understand why I roar when i do. Understand my agony.”
Tester's 8-year-old daughter told police she was asleep in bed with her father when she was awoken by a man beating him and wielding what the young girl described as “a sword and a knife,” according to court documents.
“The man told her to stay in bed because he was going to kill her dad,” the police report states.
Officers say they found a blood-stained wood-splitting ax lying next to Tester’s body, in “a large pool of blood.”
Deputies described a gruesome scene, with "blood on the walls and floor throughout the residence,” the court documents state.
The young girl called her grandmother to report the death.
Authorities say they have not detained a suspect in the case so far, noting that they will be looking into the victim's cell phone records for any possible leads.
Senator Jon Tester’s press office said “his family would prefer privacy during this difficult time.”