LAS VEGAS (KLAS) – The U.S. Marshals Service was searching for a man four days after he was ordered to surrender to serve a 20-year prison sentence.

Mario Castro, 55, was sentenced on Friday morning for stealing more than $10 million from seniors and other vulnerable victims through a prize-notification scheme.

He was convicted of conspiracy to commit mail fraud after a jury found him guilty in April.

U.S. District Court Judge Gloria Navarro ordered him to surrender by 5 p.m. that same day.

As of Tuesday afternoon, Castro remained on the run.

Castro’s two co-defendants were initially ordered to surrender to serve their sentences on Oct. 16.

Miguel Castro, 58, of Las Vegas was sentenced to 19.5 years in prison.

Jose Luis Mendez, 49, of Henderson was sentenced to 14 years in prison.

Federal prosecutors asked the court for an earlier surrender date once Mario Castro failed to turn himself in.

Castro has family ties in Las Vegas, according to the U.S. Marshals Service.

The 8 News Now Investigators have learned that family members are not cooperating with law enforcement to help locate Castro.

Anyone with information about Castro’s whereabouts is urged to not approach him and to contact law enforcement.

The U.S. Marshals Service Communications Center can be reached at (877) 926-8332.