Kris Kross' Chris Kelly Died of a Drug Overdose

Acey Harper / TIME & LIFE Images

A toxicology screening found a mixture of substances in the rapper's system.

A cause of death has been named in the case of Kris Kross rapper Chris Kelly: drug overdose.

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A medical office investigator said Monday that a toxicology screening found a mixture of drugs in Kelly’s system at the time of his May 1 death, the Associated Press reports. Betty Honey of the Fulton County Medical Examiner’s office in Atlanta said it was not clear which specific drugs Kelly had used before his death, though the 34-year-old’s mother had previously told police that Kelly used cocaine and heroin the night before he died and that her son had a history of drug abuse.

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Kelly was found unresponsive in the living room of his Atlanta home, where paramedics attempted to resuscitate him. He was later pronounced dead at a local hospital.

Kelly, known as “Mac Daddy,” performed alongside Chris Smith (“Daddy Mac”) in the ‘90s. The duo was discovered by music mogul Jermaine Dupri and were perhaps best known for their 1992 hit “Jump.” They also gained notoriety for wearing their clothes backwards and extra baggy. Earlier this year, the duo performed in Atlanta at a celebration for Dupri’s So So Def record label, fueling speculation that Kelly was staging a comeback.