The investigation of Clayton Lockett's botched execution has been concluded and the results have been made public by Oklahoma's Department of Public Safety.

Lockett's execution gained national attention when it took him over 40 minutes to die after his lethal injection. At first, prison officials stated that it was a heart attack that killed him but the report indicates that it was indeed the injected drug that caused Lockett's death.

You can read the full report at: http://www.dps.state.ok.us/Investigation/14-0189SI%20Summary.pdf