WASHINGTON (AP) - The scandal involving Secret Service agents and prostitutes in Colombia may not have been an isolated event -- even though Homeland Security Secretary Janet Napolitano told lawmakers yesterday that she believed it was.
    
The Secret Service now says it's looking into whether its employees hired strippers and prostitutes in El Salvador last year in advance of President Barack Obama's visit there.
    
A Seattle TV station (KIRO) quoted anonymous sources as saying Secret Service employees received sexual favors from strippers at a club in San Salvador and took prostitutes to their hotel rooms.
    
Prostitution is legal in Colombia and El Salvador.
    
Senators, meanwhile, are questioning Napolitano's statement yesterday that she believed the Colombia incident was an isolated case.

 Republican Lindsey Graham says, "It sort of defies logic."

He says there has to be a "cultural blueprint" in order for behavior like this to get "out of control." And Sen. Joseph Lieberman says he's heard about other examples of misconduct.