Friends of an American contractor kidnapped in Saudi Arabia placed yellow ribbons on trees as family members huddled together Sunday in New Jersey and Florida and prayed for his quick release.

A purported al Qaeda statement, posted late Saturday on an Islamic Web site, included a passport-size photo of Paul M. Johnson Jr. and a Lockheed Martin business card bearing his name. The statement threatened to treat Johnson as U.S. troops treated Iraqi prisoners -- a reference to sexual and other abuses at Abu Ghraib prison in Iraq.

"I just don't want to hear bad news because I know they're sadistic," said his brother, Wayne Johnson, 48, who spent Sunday watching television news at his home in the Manahawkin section of Stafford Township, N.J.

"The more people know about it then maybe they can get him out safe," he said.

The brothers' mother, Delores Johnson, lives with Wayne Johnson, but a neighbor said her daughter had picked her up earlier in the day.

Johnson's son, Paul Johnson III of Port St. John, Fla., told NBC News that his father moved to Saudi Arabia more than a decade ago to work for Lockheed Martin Corp.

"Let him go," Johnson III said, addressing his father's captors. "It's not his fault we're over there. It's not his fault we had to go there. It was his job."

Johnson III said he was headed to New Jersey to be with family members this week.

"I would do anything I could to switch places with him in a heartbeat," said Johnson III, a drywall contractor who has a 3-year-old son his father has never met.

He said his father had been in the Air Force and worked on radio systems for Apache helicopters.

Paul Johnson Jr. was supposed to return to the United States this month for a visit, but the trip was pushed back until the fall.

"Get my dad home safely," his son said. "He doesn't deserve this. My father's a good man. I wish the Gulf War hadn't happened. It's not just my father. Everybody is losing their lives."

Lockheed Martin released a statement Sunday that said: "We believe he has been kidnapped, but we have no information on his status or whereabouts. We will continue to work with U.S. and Saudi government and military officials and the family of Mr. Johnson to provide any assistance possible. Our thoughts and prayers are with Paul Johnson and his family."

Three Westerners have been killed in the Saudi capital in a week, including Robert C. Jacobs of Murphysboro, Ill., who was killed in his parking garage Tuesday. Several Islamic Web sites were carrying links to a videotape -- purportedly from al Qaeda -- that claims to show Jacobs being killed. Jacobs, 62, worked for U.S. defense contractor Vinnell Corp.

A woman who would identify herself only as Jacobs's sister said by telephone Sunday that the family knew about the video that purported to show his slaying, but she would not comment.

"Let him go. It's not his fault we're over there," says Paul Johnson III, above, addressing the captors of his father, Paul M. Johnson Jr., an American contractor abducted in Saudi Arabia.An Islamic Web site shows this photo of Paul M. Johnson Jr. A statement purportedly from al Qaeda threatened to treat him the way U.S. troops treated Iraqi prisoners.