GUATEMALA CITY -- Investigators say gunmen have killed a congressman who was negotiating a switch to the law-and-order party of Guatemala's president-elect.

Oscar Valentin Leal Caal was gunned down along with his brother outside the headquarters of his current Democratic Freedom Revival party early Friday. Retired general Otto Perez Molina is being sworn in as president on Saturday and he tells the Prensa Libre newspaper that Leal had been receiving death threats for discussions about joining Perez' conservative Patriotic Party.

Perez has pledged to crack down on organized crime and Mexican drug cartels.

Chief investigator Fernando Gomez says the killers had abandoned their car near the scene of the shooting, which also wounded Leal's bodyguard.

More On This...