A single black hair could help bring clarity to the mysterious death of a 50-year-old Philadelphia woman who choked on a large disinfectant wipe at a care home for people with development difficulties.

Staff found Cheryl Yewdall face down on the floor, lips blue and in a pool of urine. She was taken to a hospital but died five days later. The medical examiner’s office later said it couldn’t determine how the 7-by-10-inch wipe got in her airway -- leaving unresolved whether Yewdall’s death was accidental or a homicide. No charges have been filed.

On Friday, attorneys for the victim’s family asked a judge to order DNA testing on a strand of hair that was stuck to the corner of the wipe — a potentially important piece of evidence missed by homicide investigators, according to the legal filing. A pathologist for the family detected the hair by magnifying police evidence photos of the wipe.

“Cheryl’s mom hired me to get justice for Cheryl,” attorney James Pepper told The Associated Press in an email. “The DNA analysis of this previously unaccounted single strand of hair holds the promise of getting Cheryl that justice.”

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A wrongful death suit filed by Yewdall’s mother in 2022 casts suspicion on an unidentified staff member at the Merakey Woodhaven facility in Philadelphia. The motion filed Friday included a photo of Yewdall with mostly gray hair and some darker strands. The hair that Pepper wants tested is black.

“Plaintiff’s counsel needs to ascertain whether the hair located on the wipe or the wipe itself contains any DNA not belonging to Cheryl Yewdall,” Pepper and another lawyer, Joseph Cullen Jr., wrote in their motion, which also included two blown-up photos of the hair and the wipe. One of the photos depicts a blue-gloved hand holding the wipe — the hair strand clearly visible against the white material.

Pepper contacted the homicide detective assigned to Yewdall’s case as well as the Pennsylvania attorney general’s office last week, but “neither ... have indicated a willingness to conduct additional testing on the wipe or any testing of the black hair plainly observed on the wipe,” the lawyers wrote in their motion.

Philadelphia police declined comment Friday. A message was sent to the attorney general’s office seeking comment.

The suit accuses a staff member at Woodhaven of jamming the wad down Yewdall’s windpipe. Merakey, a large provider of developmental, behavioral health and education services with more than 8,000 employees in a dozen states, has previously denied any responsibility for Yewdall’s death, which it called “a serious and tragic incident.”

Yewdall, who had cerebral palsy and profound intellectual disabilities, lived at Woodhaven for four decades. Evidence previously uncovered by the family shows Yewdall suffered a broken leg that went undiagnosed, and had other injuries at Woodhaven in the year leading up to her death on Jan. 31, 2022.

Yewdall, who had limited verbal skills, often repeated words and phrases she heard other people say, a condition called echolalia. In a conversation recorded by Yewdall’s sister, the suit notes, Yewdall blurted out: “Listen to me, a———. Settle down baby. I’m going to kill you if you don’t settle down. I’m going to kill you, a———.”

Pepper has said Yewdall’s outburst implied she had heard those threats at Woodhaven.

Merakey declined comment on the family’s request for DNA testing.

The Lafayette Hill, Pennsylvania-based company plans to close Woodhaven in January 2025 and relocate dozens of residents to smaller community-based homes. It has said the closure is in line with state policy and a long-term national shift away from larger institutions.