An alleged serial killer in Texas is going on trial this week for one of the nearly two dozen murders he’s been charged with committing.  

The capital murder trial for 49-year-old Billy Chemirmir begins Monday in Dallas in the death of Mary Brooks, an 87-year-old woman who was found dead on the floor of her Dallas-area condo in early 2018. 

The charges against Chemirmir grew in the years following his 2018 arrest, as police across the Dallas area reexamined the deaths of older people that were considered natural before families raised alarm bells. Four indictments were added this summer.

Texas alleged serial killer in court

FILE: Accused serial killer Billy Chemirmir looks back during his retrial on April 25, 2022, at Frank Crowley Courts Building in Dallas.  (Shafkat Anowar/The Dallas Morning News via AP)

Chemirmir was convicted in April of capital murder in the smothering death of 81-year-old Lu Thi Harris and sentenced to life in prison without parole. He will receive the same punishment if convicted in Brooks' death. His first trial in Harris' death ended in a mistrial last November when the jury deadlocked. Chemirmir has maintained his innocence. 

In March 2018, 91-year-old Mary Annis Bartel survived an attack and told police that a man had forced his way into her apartment at an independent living community for seniors, tried to smother her with a pillow and took her jewelry. Her survival and interviews with police set Chemirmir's arrest in motion. 

Police said they found Chemirmir the next day in the parking lot of his apartment complex. He was holding jewelry and cash and had just thrown away a large red jewelry box. Documents in the box led them to the home of Harris, who was found dead in her bedroom.

At trial, prosecutors presented evidence that Harris and Chemirmir were checking out at the same time at a Walmart just hours before she was found dead. 

TEXAS GIRL, 12, WHO SHOT FATHER IN MURDER PLOT TO KILL FAMILY DEAD FROM SELF-INFLICTED GUNSHOT WOUND: POLICE

In a video interview with police, Chemirmir told a detective that he made money by buying and selling jewelry, and that he had also worked as a caregiver and a security guard.

Most of Chemirmir's alleged victims lived in apartments at independent living communities for older people. The women he's accused of killing in private homes include the widow of a man he had cared for while working as an at-home caregiver.

Brooks' grandson, David Cuddihee, testified that he found her body on Jan. 31, 2018. He said she had sometimes used a cane but was still healthy and active.

Police testified that grocery receipts showed Brooks was at Walmart the day before her body was found. Surveillance video from the store showed a vehicle matching the description of Chemirmir's leaving just after Brooks, going in the same direction.

Dallas County District Attorney John Creuzot decided to seek life sentences rather than the death penalty when he tried Chemirmir on two of his 13 capital murder cases in the county. 

CLICK HERE TO GET THE FOX NEWS APP

Prosecutors in neighboring Collin County haven't said if they will try any of their nine capital murder cases against Chemirmir.

The Associated Press contributed to this report