Alma Murdough's attorney, Derek Sells, said he will also ask the city to preserve all communications and 911 recordings regarding former Marine Jerome Murdough's death on Rikers Island. Sells scheduled a news conference for Friday afternoon.
He filed a notice of claim, the first procedural step necessary for a civil suit against the city, with the comptroller's office on April 30 on behalf of the inmate's 75-year-old mother. In it, he writes that the 56-year-old Murdough's death was caused by carelessness and negligence by Department of Correction employees.
Prosecutors in the Bronx are investigating the death.
"This case involves a tragic incident and we will review the lawsuit and respond accordingly," said Nick Paolucci, a spokesman for the city's law department.
Corrections officials have declined to comment, citing the ongoing criminal investigation.
The Associated Press first reported in March on suspicions about Murdough's cause of death. One official who spoke at the time on the condition of anonymity described him as having "basically baked to death."
Citing a preliminary DOC investigation, court documents filed last month in a separate federal court case show that Murdough's internal body temperature, taken nearly four hours after he was discovered unresponsive in his cell in the early hours of Feb. 15, was 103 degrees. It said the cell was 101 degrees. Murdough was slumped at the edge of the foot of his bed with "a pool of vomit and blood on the floor," the documents said.
A spokeswoman for the medical examiner's office says the exact cause and manner of Murdough's death have not yet been determined, pending further studies. But the court documents show the medical examiner investigator assigned to Murdough's case preliminarily found he likely died of hyperthermia.
Murdough was on psychotropic medication at the time of his death, which experts say can make people sensitive to heat. DOC officials have said he was left unattended for hours.
Murdough was arrested Feb. 7 on a misdemeanor trespassing charge for sleeping in an enclosed stairwell on the roof of a Harlem public housing building and was sent to Rikers Island after being unable to make $2,500 bail, according to court records.