UPDATED: March 27, 2018  3:25 PMBy Andrea Lucia

UPDATE: Plano Police have determined that murder suspect Billy Chemimir has used the alias name of Benjamin Koitaba while operating as a health care professional. 

PLANO, Texas (CBSDFW.COM) – A retirement complex in Plano is under the watchful eye of police, as officers investigate an attack on an elderly woman and several suspicious deaths there.

READ MORE: Carroll ISD Parents Pack School Board Meeting Following Administrator's Secretly-Recorded Holocaust Comment

“I think everyone’s more cautious,” said Mary Beth Wells, who lives in the Preston Place retirement community.

The assault on a 91-year-old there last week was one of three throughout North Texas now publicly linked to Billy Chemirmir, who’s been charged with both capital murder and attempted capital murder.

Billy Kipkorir Chemirmir (credit: Dallas County Sheriff’s Department)

On March 19, Plano police believe Chemirmir forced his way into the woman’s apartment, telling her “Go to bed. Don’t fight me,” according to an affidavit.

He’s suspected of trying to suffocate her stealing her jewelry.

“She’s just a sweet lady. She’s been here a long time,” said Wells.

Dallas, Plano, Richardson and Frisco Police are all investigating the man accused of posing as maintenance worker and using his health care experience to target elderly women living alone. In each of the three cases police have identified, the women’s jewelry was stolen.

“We’re trying to flood the whole area, to make sure everybody knows about this,” said Officer David Tilley, a spokesperson for the Plano Police Department.

READ MORE: Police From All Over Rally To Lift Spirits Of North Texas Child Battling Cancer

The department has opened a 24-hour tip line being manned by five officers.

Monday, in a post to the Nextdoor app, it asked anyone whose loved one died under “suspicious circumstances” to call in.

Eventually the department plans to review every single death of an elderly woman in the area where there was no witness.

“It’s going to be a very tedious process. It’s going to be very time consuming,” said Tilley.

Plano police and the Preston Place community have already played a major role in the investigation spanning both Dallas and Collin counties.

It was someone at the retirement community who noticed a suspicious silver Nissan Altima on March 15 and took down the license plate. When police came asking questions following the attack on March 19, that license plate was what led them to first look at Chemirmir as a suspect.

Police confirm they’re reviewing several suspicious death at the complex, which one resident told CBS11 occurred near last week’s attack.

Neighbors told CBS11 they were rattled by the news, but relieved to learn a suspect is behind bars.

MORE NEWS: 1-Year-Old Dallas Boy At Center Of Amber Alert Found Safe

“I’d like to wring his neck myself,” said Wells.