DALLAS (CBSDFW.COM) – Shortly before her mother’s death, Shannon Dion took her on a cruise to Alaska.

“My mother climbed four flights of stairs on the ship because she couldn’t wait for the elevator,” she recalled of 92 year old Doris Gleason. “Mentally and physically, she was outstandingly healthy.”

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Weeks later, she stopped by the Tradition at Prestonwood retirement complex in Dallas to pick her up from church and was stunned to discover her dead.

“For one hour, I believed my mother had died naturally,” she said.

Then, Shannon asked funeral home workers for her mother’s jewelry. A thick gold bracelet her mother often wore was missing. So was the guardian angel necklace, matching Shannon’s own, that she never took off.

“The necklace… she showered, slept… it doesn’t leave,” Shannon said.

Police documented the theft, but Shannon was far from satisfied.

“The bag of stuff,” she said, pulling out a bag filled with stacks of paper, held together with paperclips and labeled with sticky notes.

She requested police reports for any crime at her mother’s complex.

“Everything at this address,” she said, pointing at the address near the top of each of the file.

She found a record of a “suspicious person… seen on numerous occasions” who had falsely claimed “he was there to check for pipe leaks.”

She also found three other women at the complex who had died recently and had jewelry reported missing.

A year and a half later, in March of 2018, Plano firefighters resuscitated a woman found unconscious at home in the Preston Place senior living apartments. She told police a man forced his way in, tried to suffocate her, and stole her jewelry.

Investigators soon found a pattern among women who had recently died at the complex and realized, for the first time, they were looking for a killer.

“I got the call that my mother’s death was being investigated as a homicide, which is horrifying,” said Shannon.

Today, Billy Chemirmir stands indicted in the murders of 18 elderly women across North Texas.

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“As I met other victim families who had the exact same story and experience, we all felt something had to change.

Shannon founded the non-profit, Secure Our Seniors’ Safety, to take their fight to the state capitol.

Together victims’ families are helping craft legislation to make retirement communities safer.

Chemirmir, police believe, repeatedly entered the same senior living centers, murdered residents, and escaped undetected.

In civil lawsuits, the centers claimed they were not culpable, cooperated with police, and relied on investigative agencies who initially determined the deaths had been from natural causes.

Despite the illusion of a secure environment, families say red flags were ignored and residents left unaware.

“You’ve got a market that rewards homes that are able to hide their problems. We want to flip that,” said State Senator Nathan Johnson, who is proposing a state program to certify facilities that can show they meet a high standard of security and transparency.

“Give us all some peace of mind when our parents go there or when we go there,” said Johnson.

Victims’ families are lobbying too for stricter regulations of cash for gold businesses, where police say Chemirmir sold stolen goods.

“The items are either immediately resold or immediately melted down,” said Dion, whose mother’s jewelry was never recovered.

Under a new law, shops would have to show they keep detailed notes of the items purchased and hold gold for a set amount of time.

The nonprofit’s work, Shannon said, helps give some meaning to her mother’s death.

“We believe it’s time to care for those who’ve cared for us,” she said.

It’s also given her hope.

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“I haven’t had that feeling in a very long time.”