In a rambling explanation punctuated with profanity, Thomas J. Fox told a police investigator soon after Lori Baker was found murdered that he didn't kill her and regretted leaving a key in the door of her apartment for an intruder.

"I didn't do nothin' to her, man," Fox told Drew Evans of the state Bureau of Criminal Apprehension after the murder in 2011. "Why would I have a reason to hurt her? For what reason? I'm telling the truth, man, Lori had no trouble with me, man."

Fox, 46, is on trial in Washington County District Court on charges of premeditated first-degree murder. Baker, a 39-year-old Oakdale nanny, was found stabbed 48 times on the floor beside her bed. Fox, her apparent boyfriend, was arrested a few days later at a downtown Minneapolis bus depot.

"Who am I going to talk to who will say, 'Thomas would never kill that woman,' " Evans said in a recording of the interview played for the jury Thursday. "Would you tell us if something got out of hand?"

In cross examination, defense attorney Virginia Murphrey questioned Evans about whether he further investigated leads that Fox had given him about other people who might be involved, establishing that Fox had been the principal suspect from the start.

"You were looking for particular things that you wanted to find, not the full picture, right?" she asked him.

County Attorney Pete Orput's final witness was Dr. Victor Froloff, assistant Ramsey County medical examiner. Orput showed Froloff a series of autopsy photographs and asked him to explain the nature of numerous knife wounds on Baker's face, back, chest and forearm. She also had a blunt force injury to her left eye, Froloff said, inflicted by a fist or heavy object.

Under questioning from Murphrey, Froloff said he couldn't determine the identity of the attacker from the autopsy results.

Defense attorneys called their first witness, handwriting examiner Lisa Hanson, Thursday afternoon. Hanson told defense attorney Rebecca Waxse that handwriting on notes found in Baker's apartment didn't match handwriting found in her checkbook but didn't elaborate on the significance of that.

Kevin Giles • 651-925-5037