Kris Kross Rapper Official Cause of Death Overdose

7/1/2013 4:22 PM PDT

Kris Kross Rapper Chris Kelly -- Official Cause of Death ... Drug Overdose

Breaking News

It's not surprising, but it's official ... Kris Kross rapper Chris Kelly died from a drug overdose.

An investigator from the Fulton County Medical Examiner's Office in Atlanta said a toxicology screening showed the 34-year-old died with a fatal mixture of drugs in his system.

The investigator didn't specify which drugs, but as we reported, Chris' mother told police the rapper had been doing cocaine and heroin the night before he died on May 1st.

The video TMZ posted -- showing a wasted Chris trying to rap just hours before his death -- appears to back up the Medical Examiner's findings.

In addition to the footage, Kelly also had a long history of drug abuse.