Chris Kelly of the rap group Kriss Kross died of a drug overdose, a medical office investigator told the Associated Press on Monday.

The 90’s musician died on May 1 from a mixture of drugs, confirmed Betty Honey from the Fulton County Medical Examiner’s office in Atlanta. The office did not release information about the type of drugs found in Kelly’s system.

Kelly’s mother Donna Kelly Pratt told police that her son used cocaine and heroin the night before his death, according to the Associated Press report. She also told police that he had an “extensive history of drug use.”

The 34-year-old was found in his Atlanta home by paramedics and could not be resuscitated.

Kelly and Chris Smith of Kriss Kross were best known for their 1992 hit “Jump.” The trend-setting pair was also known for wearing their clothes backwards.

Kelly’s mother released a statement to Us Weekly:

“To millions of fans worldwide, he was the trendsetting, backwards pants-wearing one-half of Kris Kross who loved making music. But to us, he was just Chris — the kind, generous and fun-loving life of the party. Though he was only with us a short time, we feel blessed to have been able to share some incredible moments with him. His legacy will live on through his music, and we will forever love him.”