After crossing into the United States from Mexico last year, Jose Manuel Martinez was arrested on one count of murder and sent to Alabama. But, once investigators across the country heard his name, many more wanted to question him.

Now, Martinez, 51, is in Central California being charged with killing nine others, and that's not all.

He admitted to investigators that he killed up to 40 people, a prosecutor said Wednesday. He also admitted that these murders were drug related.

Errek Jett, the district attorney in Lawrence County, Ala. believes Martinez because of the details he was able to provide.

Defense attorney Thomas Turner, who is representing Martinez in his Alabama case, says he is innocent of the murder in Alabama and even called him "polite and likable."

But California prosecutors couldn't disagree more. They say he has killed at least nine victims in California dating back to 1980 and ending in 2011.

He's accused of shooting a man on his way to work, shooting another man who was working on a ranch, and even killing a man in his bed while his four children were home.

Besides murder charges, Martinez is charged with kidnapping and attempted murder as well.

All of the California charges make him eligible for the death penalty.

Martinez has lived intermittently in the small farming community of Richgrove, Calif. and has been in and out of state prison on drug charges.

Martinez's mother, Loreta Fernandez doesn't believe that her son committed these murders.

Martinez remains in custody in Alabama and he will face a trial in June.