A man charged with the murder of nine people in California as admitted to authorities that he has killed as many as 40 people while working as an enforcer for a drug cartel.
Jose Manuel Martinez, 51, was arrested in Arizona in 2013 over a murder he is alleged to have committed in Alabama, a charge he denies.
When in custody, however, investigators from across the US interviewed him about cartel murders in their state.
After his trial in Alabama, Martinez is due to face nine charges murder charges in California, including four charges of kidnapping and murdering for financial gain, crimes which would make him eligible for the death penalty.
During the investigations, one prosecutor has said that Martinez confessed to as many as 40 killings during his career with the cartel.