Billy Chemirmir, 49, is facing a capital murder trial over the killing of 87-year-old Mary Brooks, who was found dead in her Dallas condo in 2018.
Authorities initially believed Brooks had died of natural causes, even though family raised alarm bells that many of her favourite pieces of jewelry was missing. Her shopping bags were left on the counter, and a coral necklace and several diamond rings were gone, according to prosecutors.
It was only weeks later when Chemirmir was arrested for a separate attack that police began to suspect his involvement.
In that case, Mary Annis Bartel, 91, told police that a man had forced his way into her apartment at Parkview Elderly Assisted Living facility in Frisco, attempted to smother her with a pillow and stole her jewelry, the Associated Press reported.
Ms Bartel, who died in 2020, described in a taped police interview that Chemirmir had appeared suddenly as she opened her front door a man wearing green rubber gloves before forcing her to the ground and holding a pillow over her face.
Chemirmir was arrested the next day in the parking lot of his apartment with jewelry and cash.
Documents found in a box the murder suspect was attempting to dispose of led police to the home of 81-year-old Lu Thi Harris, who was found dead in her bedroom, lipstick smeared on her pillow, the Associated Press reported.
As more unexplained deaths came to light, authorities in Texas said they were planning to review hundreds of deaths previously thought to have been due to natural causes.
They eventually charged him with 22 murders, including four new indictments this summer, in addition to several counts of attempted murer.
Chemirmir, who has maintained his innocence, was found guilty of Harris’s murder at a retrial in April and sentenced to life without the possibility of parole after prosecutors declined to seek the death penalty.
The jury in a previous trial in November had been unable to reach a verdict.
This week, relatives of Mary Brooks said they were planning to be in court to face Chemirmir. Daughter Loren Adair Smith told the AP the trial would bring a “huge bag of mixed feelings”.
“At the same time of having that dread feeling, we are really glad to go back and bring this chapter to a close,” Ms Smith told the outlet.
In affidavits, police have said that surveillance footage placed Chemirmir at a Walmart store at the same time that Mary Brooks had been shopping there, a day before her body was found.
Chemirmir is believed to be North Texas’s worst serial killer, and one of the worst the century in the US, Dallas County District Attorney John Creuzot said during his closing address in the first trial.
Mr Creuzot told the Dallas Morning News in an interview that he had not sought the death penalty due to the cost of appeals and length of time it takes for an execution to be carried out.
Chemirmir still faces nine capital murder cases in neighbouring Collin County. Most of Chemirmir’s alleged victims lived in assisted living facilities,
Chemirmir told police during interviews that he had worked as a caregiver and security guard, and made money buying and selling jewelry. Per the AP, he had worked as a nurse in his native country of Kenya, but appears to not have been legally working in healthcare in the US.