Syracuse, NY -- A Syracuse man accused of fatally smashing a woman's head on a concrete floor was not arrested until he showed up at police headquarters days later griping about his seized car, a police officer testified today.

Kevin Johnson, 47, kept talking about his car when Detective Steven Stonecypher began his interrogation into the October 2016 assault of Kimberly Rhoades.

But during the interrogation, a detective told Johnson that Rhoades had died. The detectives left the room sometime later.

"Oh my God, she wasn't supposed to die," Johnson said to himself, in a statement recorded on video.

Johnson, a pimp, attacked Rhoades, who was working for him as a prostitute, because she owed him money, prosecutor Jeremy Cali has said.

A witness told police that Johnson broke into 134 Eureka St. through a window and attacked Rhoades in the basement.

"I want my (expletive) bitch, I'll kill you," the witness said Johnson told him before the assault.

Police were still looking for Johnson several days later when he came to police headquarters looking to get his car back.

That's when he made the apparent confession.

But Johnson's words are not a sure bet to be admissible at trial.

Assigned defense lawyer Charles Keller noted today that Johnson's words -- "Oh my God, she wasn't supposed to die" -- came after he'd made references to a lawyer.

That should have ended the interrogation, Keller said.

On top of that, Johnson was alone in the interrogation room and apparently unaware that cameras were rolling.

"These cameras are a blessing and a curse," Keller noted today, suggesting that using his client's statements to himself could even amount to eavesdropping by police. (Cameras were originally installed so judges and juries did not have to rely on an officer's recollection of what a suspect said during an interrogation.)

Keller argued today that police continued to talk to Johnson -- even after he'd mentioned a lawyer -- to get a reaction out of him. That included mentioning that Rhoades had died, something that Johnson clearly hadn't known yet.

But prosecutor Jeremy Cali defended the officers' actions. He noted that Johnson had been read his Miranda (Constitutional) warnings before the interrogation and had waived his rights.

Cali also said that Johnson never unequivocally asked for a lawyer.

In one case, Johnson was asked when he saw Rhoades last. He said he didn't remember, then said, "Maybe I need to talk to a lawyer," Stonecypher testified.

Stonecypher said that he asked Johnson if he wanted to end the interrogation, and Johnson kept talking over him.

Eventually, Stonecypher said, detectives left the room to call the Onondaga County District Attorney's Office. A defense lawyer was called down to police headquarters, but did not arrive for several hours.

In the meantime, detectives continued talking to Johnson. They did not ask any questions, but made statements to him.

Keller called those statements unconstitutional. He argued that police should have left Johnson alone as soon as he mentioned a lawyer.

Instead, officers told Johnson, among other things, that Rhoades had died. After they left the room again, and Johnson was by himself, the defendant made the statement to himself.

Cali said that police weren't trying to elicit a response from Johnson; they were simply telling him that fact because they had already decided to charge him with her death.

Later, a lawyer did arrive and Johnson declined to talk further to police. He was then charged with Rhoades' death.

County Court Judge Stephen Dougherty will decide whether Johnson's recorded utterance can be used against him at trial.

Also today, Stonecypher testified about a witness, Donald Mothersell, to the murder who identified Johnson out of a photo lineup.

Mothersell told police that he was with the victim, Rhoades, that day when she left left to have sex for money.

Rhoades went outside, then came running in. Rhoades said, "They set me up! They set me up!" the witness told police. She locked the door and ran into the kitchen.

Johnson, who the witness knew as "Chills," climbed in through a window. On his way by, Johnson threatened Mothersell: "I want my (expletive) bitch, I'll kill you."

Johnson assaulted Rhoades in the basement, punching her in the face and hitting her head on the floor, the witness said.

Johnson is facing a murder charge punishable by up to 25 years to life in prison. He's also facing burglary and promoting prostitution charges. He remains in jail as his case continues.