The investigation into Ally Kostial’s murder uncovered Brandon Theesfeld’s activities after learning that his girlfriend might be pregnant. His online search history showed the search terms “abortion services” and “abortion pills.” However, Kostial’s autopsy showed that she was not pregnant at the time of her death, and there was no evidence that she ever had been.

Theesfeld also searched for suppressors, silencers, and hollow-point ammo for a Glock pistol that his father owned (via New York Post). When Theesfeld was apprehended days after the murder, the murder weapon was found in his truck, and he was wearing clothes with blood on them. A search in his apartment revealed a letter addressed to his parents, which read, “Something in me just doesn’t work. I’ve always had terrible thoughts. I’ve always had these feelings. I just kind of fell off. I think this is the end for me. I’m either going to prison or going to die. I know I’m going to get caught.”

In August 2021, Theesfeld pleaded guilty to first-degree murder and was sentenced to life in prison. During his sentencing, Theesfeld read a statement and apologized to Kostial’s family. “I wish I could take it all back but I can’t … I have asked God to forgive me. I hope you can find it in your heart to forgive me,” he said, as reported by Dark Horse Press Now.