A man charged with killing 18 older women in the Dallas area over two years has been found guilty of murder and sentenced to life in prison in one of the cases against him.

Jurors took about 45 minutes to convict Billy Chemirmir, 49, in the March 2018 smothering of 81-year-old Lu Thi Harris.

After Chemirmir and Ms Harris were at the same Walmart, he went to her home, killed her, and stole her jewellery, prosecutors said.

It was the killer’s second trial – after the first jury to hear the case deadlocked in November.

Prosecutors did not seek the death penalty so state District Judge Raquel “Rocky” Jones sentenced Chemirmir to life in prison without parole.

Chemirmir, who has maintained his innocence, is charged with murdering 12 other women in Dallas County and five in nearby Collin County.

Dallas County district attorney John Creuzot said he plans to try Chemirmir for at least one more death.

Relatives of those he is accused of killing praised Thursday’s verdict at an emotional press conference.

“This one conviction represents justice for all of the families,” said Shannon Dion, whose 92-year-old mother, Doris Gleason, was killed in 2016.

Defending, Kobby Warren said during closing arguments that prosecutors had not proved beyond a reasonable doubt that Chemirmir was ever at Ms Harris’ home, calling the state’s case “all bark, no bite”.

As in the first trial, the defence did not call any witnesses and Chemirmir did not give evidence.

Prosecutor Glen Fitzmartin told jurors he gave them more than enough evidence to convict.

“This is an easy decision, mainly because we bit so much off,” said Mr Fitzmartin, who noted that when Chemirmir was arrested, he had Ms Harris’ jewellery and the keys to her home.

Jurors also saw CCTV footage of Ms Harris and Chemirmir at Walmart on the day she was found dead.

Prosecutors also presented evidence to jurors about an attack that 91-year-old Mary Annis Bartel survived the day before Ms Harris was killed and the killing of 87-year-old Mary Brooks about six weeks earlier.

Chemirmir was arrested the day after Ms Bartel said a man forced his way into her apartment and held a pillow over her face.

Mr Fitzmartin said police subsequently found that a few days earlier there had been a report of a suspicious person at the independent living community where she lived.

A licence plate number led officers to Chemirmir.

Police detectives said they went to Chemirmir’s nearby apartment complex and watched as he drove into the car park.

They said he threw items into a dumpster and then, as they got him out of his vehicle, he was holding jewellery and cash in his hand.

Police said that a large red jewellery box in the dumpster contained documents that led them to Ms Harris’ home. They found her dead in her bedroom, with lipstick smeared on her pillow.

The number of people Chemirmir was accused of killing grew as authorities reinvestigated deaths previously thought to be natural.

Most of the people were found dead in their apartments at independent living communities for older people, where Chemirmir has been accused of forcing his way into apartments or posing as a handyman.

Some lived in private homes, including Harris and the widow of a man Chemirmir had cared for in his job as an at-home caregiver.

MJ Jennings, whose 83-year-old mother, Leah Corken, was killed in 2016, said she hopes the conviction will be “the first step of healing for all of these families”.

Ms Bartel died in 2020 but jurors heard a taped deposition of her describing opening her door on the day she was attacked.

She said she immediately focused on green rubber gloves the person was wearing and tried to push the door shut but was overpowered.

“He said: ‘Don’t fight me, lie on the bed,’” Ms Bartel said.

She said her attacker “slammed” the pillow to her face and used “all his weight to keep me from breathing”.

She said she could not remember details about the man’s appearance.

Ms Bartel, who lost consciousness, later discovered she was missing her wedding band, diamond engagement ring and other jewellery.

Prosecutors presented evidence that Chemirmir listed jewellery belonging to Ms Bartel and Ms Brooks for sale online.