Billy Chemirmir was convicted in the slayings of two elderly women at high-end Texas retirement homes and indicted for the killings of 20 more, but if one woman had not survived his attempt at smothering her, he may have never been caught.

Less than a year after he was killed by his cellmate, suspected serial killer Billy Chemirmir is the subject of a just-released Paramount+ docuseries “Pillowcase Murders.” He was killed in a Texas prison by a cellmate in 2023, officials said.

Over a two-year span, authorities said Chemirmir used his work as a caregiver to prey on elderly women in the Dallas area, posing as a maintenance person or medical professional to get into their homes before asphyxiating them and stealing their valuables, including $30,000 worth of jewelry in one instance.

Smothering leaves little evidence of foul play, and due to the women’s advanced ages, their deaths were repeatedly attributed to natural causes.

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The daughter of Marilyn Cardillo Bixler, who was found dead on the floor of her apartment in September 2017, previously told Fox News Digital that she did not suspect her mother had been murdered when she found her dead.