A Dallas man charged in the murder of an 81-year-old woman is now accused of robbing and attempting to kill two other older women.

The investigation into the string of attacks has prompted the Dallas Police Department to review 750 unattended death cases to see if there are any similarities.

"In Dallas alone there are over 750 elderly females where we are going to go back and review those cases on, so it will be a monumental task," said Dallas Police Executive Assistant Chief David Pughes.

Other local police departments will be review their cases, as well, making the number grow into thousands. NBC 5 has learned similar reviews are also being conducted by several other North Texas police departments.

Billy Chemirmir, 45, is charged with the capital murder of Lu "Kim" Harris, a woman who was found dead in her North Dallas home Tuesday.

Plano police said they identified Chemirmir as a suspect in the attack of a 91-year-old woman who was smothered and robbed inside her Plano apartment on March 19.

An arrest affidavit said Chemirmir forced his way into the woman's apartment and told her to, "go to bed, don't fight me." The victim lost consciousness but was later revived by Plano Fire Rescue and told investigators the person stole jewelry from her. Plano police said they identified Chemirmir as a suspect from a license plate at the complex.

Following up on that lead, investigators were conducting surveillance on Chemirmir in Dallas on March 20 when they watched him throw a jewelry box in a trash bin. Police retrieved the box and noticed there as a name inside.

Officers tracked that name to Harris’ North Dallas home where investigating officers found her deceased.

Plano Police Chief Greg Rushin said Harris, who was described by neighbors as a sweet, generous woman who lived alone, had been smothered with a pillow.

Dallas police obtained a capital murder warrant for Chemirmir. He was arrested and booked into the Dallas County Jail where he is being held on $1 million bond.



At the time of his arrest, Chemirmir was also wanted for an attempted capital murder case in Frisco that took place in October 2017.



In that case, police said Chemirmir posed as a maintenance worker and forced his way into the home of a 93-year-old woman living at Parkview Elderly Assisted Living in Frisco.



The victim told police she too was smothered with a pillow and began praying because she thought she was going to die. The woman's attacker, police said, stole jewelry from her as well.

Plano police said Chemirmir has been employed in the past as a health care worker and they believe there may be more victims.

"Chemirmir uses healthcare experience to his advantage in targeting and exploiting seniors, some of the most vulnerable members of our community. This is terribly disturbing," said Plano Police Chief Gregory Rushin.

Lisa LeMaster, a spokesperson for Solvere Senior Living confirmed to NBC 5 the March 19 incident in Plano happened at Preston Place, a senior community it manages. The company released the following statement Friday night:

“We are horrified, disgusted, and angry about the recent events involving seniors in the Dallas area but also relieved to learn a suspect has been arrested and charged. Our thoughts and prayers are with the residents and families directly affected by these crimes, including those in our community. Solvere assumed management of this property just over a month ago after it was purchased. Following our takeover of the community’s management, we initiated a routine review of the community’s safety and security procedures and equipment. Based on our review, and particularly in light of recent events, including the possibility of thefts from residents who recently passed away, we quickly began to implement changes to improve the safety and security of the community’s residents. Solvere has been assisting Plano Police in any way possible with its investigation. In addition, the company implemented a significant overhaul of the community’s security equipment and protocols. In just a few days, we installed cameras, changed all gate codes and reprogrammed key fobs, implemented a background check program for third party vendors, and issued new uniforms as well as name badges for our employees. Safety is our highest priority.”

Anyone with information is asked to call 972-941-5785.

It is not clear if Chemirmir has obtained an attorney.