DALLAS (CBSDFW.COM) – Alleged serial killer Billy Chemirmir laughed and smiled at moments during hours of police interviews following his arrest in 2018.

“You’re going to jail for murder,” said Dallas Police Detective Brian Tabor, in video played on the third day of Chemirmir’s capital murder trial.

“Murder?” replied Chemirmir in disbelief.

He repeatedly denied he’d murdered the victim, Lu Thi Harris, in her Dallas home.

“What house?” he asked.

“The house in Dallas,” said Tabor.

“I did not go to a house in Dallas,” he said.

Billy Chemirmir police interview

Chemirmir said he’d purchased an envelope of $2 bills a few days earlier from someone in Fort Worth.

He said he’d bought a jewelry box from someone else just twenty minutes before his arrest.

But, he struggled to provide details on who he bought the items from, how they’d been in contact, and how much he paid.

“He’s having to think about what he’s going to tell me,” noted Tabor on the witness stand Wednesday, Nov. 17.

When asked during the interrogation why he’d thrown a jewelry box he claimed he had just purchased into the dumpster at his apartment complex, Chemirmir responds, he decided he didn’t want it.

“The person that you murdered. You had her property. You had her money. You had her jewelry. And, you had her jewelry box,” said Tabor.

Jurors watched surveillance video from a Walmart in Dallas that shows Harris and Chemirmir cross paths hours before her death.

There’s no apparent interaction between the two, but they’re seen leaving the store within less than a minute of each other and driving off in the same direction.

Later in the day, the prosecution played video from the same Walmart showing Mary Brooks, of Richardson, at the store on January 30.

Chemirmir can be seen visiting the store at the same time as well. The next day, Brooks was found dead in her home.

Brooks’ daughter testified a safe and jewelry were missing from the house.

“She wore it every single day,” Anne Brooks testified of her mother’s coral necklace.

“Did you find it?” asked lead prosecutor, Glen Fitzmartin.

“No,” said Brooks.

Testimony is set to resume Thursday morning in what Judge Rocky Jones has previously said will likely be the final day of trial.

If convicted for capital murder, Chemirmir will receive an automatic sentence of life in prison.