LAFAYETTE — The sister of Michelle Steven, who was strangled and beaten in a 1989 attack, told jurors Thursday that she never suspected Louis Joseph George was the attacker until he threatened to do to her what he had done to her sister years earlier.

George, 49, is on trial for second-degree murder. He is accused of beating and strangling Steven in an April 1989 attack that left her lingering in a coma for 12 years until her death in 2001 at age 35.

George became a person of interest in the case early on, but he was not arrested until 2007, after his DNA was matched to evidence taken from the scene, Assistant District Attorney Keith Stutes has said.

Closing arguments are expected to begin Friday morning. The defense rested late Thursday afternoon without calling any witnesses.

The state’s last witness was Steven’s sister, Debra Steven Anderson, who testified Thursday she was dating George at the time of the attack on her sister.

Hours before the 1989 attack, Anderson said, George left her home and returned the next morning with a swollen and injured hand.

When she asked him about it, George told her that he injured his hand while painting a tin roof, Anderson testified.

The prosecution has alleged George broke into Steven’s home and tried to force her to have sex with him. When she refused, George beat her and strangled her, leaving her unconscious.

Anderson testified that George told her in 1993, “I should have put your butt where I left your sister.”

Anderson said she fled to Texas a few days after that threat.

A second person testified Thursday to hearing a similar threat from George.

Jacqueline Riser, who said she knew George and members of the Steven family, testified that she had a falling out with George some time after the attack.

“Did you ever have an occasion to have a conversation with Mr. George that specifically addressed what happened to Michelle?” Stutes asked her.

“Yes. He said if I kept messing with him that what happened to Michelle would happen to me,” Riser said.

Thomas Clemens, an inmate at the Lafayette Parish Correctional Center, testified that George shared information with him about the case while the two shared a cell at the prison.

Clemens said George told him that he and Michelle Steven had a previous sexual relationship and that he restrained her because she became violent with him and tried to hit him.

George said he tried to talk to her, but she would not listen, Clemens testified.

George then stopped talking and “he kind of looked down, like he was thinking about something,” Clemens said.

Afterward, George refused to talk any further about the case, said Clemens, who testified that he then wrote a report about the incident and sent it to the District Attorney’s Office.

George Schiro, DNA technical leader at the Acadiana Crime Lab, testified that George’s DNA could not be excluded as a minor contributor to a blood sample taken from Steven’s pants. Steven was the major contributor to the sample, Schiro said.

Schiro picked up the case in 2005 after the Lafayette Parish Sheriff’s Office began examining the case in its newly created cold case division.

Schiro got the match in December 2006, he said.

Asked to relate what that match meant, Schiro said there was a 1-in-11,000,000 chance that someone else could provide a sample that could also not be excluded as the source.

George’s attorney, Harold D. Register, questioned why only certain evidence samples were tested as opposed to other samples, such as Steven’s fingernail clippings, which could have contained DNA samples if she fought with her attacker.

Schiro said he tested the sample from Steven’s pants because it was one sample he felt gave him the best chance at getting a match.

During questioning, Schiro said he also tested a semen stain on the carpet, which was linked to Steven’s brother, Darren, who also lived at the house.

Schiro tested a stain on a bedspread at Steven’s home and found that another man, Henry Senegal, could not be excluded as the source for that sample.

Jurors also heard testimony from David Gabriel, Michelle Steven’s boyfriend at the time.

Gabriel said he discovered his girlfriend lying beneath a blanket on the floor of her home.

“The body was kind of trembling,” Gabriel said.

When he pulled back the blanket, he saw a face that was bloody and bruised, he said.

“She was unrecognizable,” Gabriel said.