The search for escaped Texas death row inmate Charles Victor Thompson was nationwide Sunday.

The Harris County Sheriff's Department says it's still following up on tips and possible sightings, but none has worked out so far.

The U.S. Marshals Office is offering a $10,000 reward for Thompson's capture.

He's been designated a federal fugitive as well.

Thompson, 35, of the Houston suburb of Tomball, was condemned in 1999 for the shooting deaths a year earlier of his ex-girlfriend and her boyfriend.

He freed himself from handcuffs and left jail in civilian clothes Thursday. He remains at large, and frustrated law enforcement officials are citing multiple instances of human error leading to the escape.

Thompson fooled at least four jail employees into thinking he worked for the state attorney general's office.

Lt. John Martin, a sheriff's spokesman, says investigators believe Thompson had inside help.

Several relatives of Thompson's victims have gone into hiding or agreed to police protection.