Three men who allegedly gained entry to a Downey residence by pretending to be police officers were jailed on robbery charges, police said. Police said the three men knocked on the door of a home in the 7800 block of Alderdale Street and said they were police. Then, waving pistols, they forced their way inside, handcuffed a couple and their two teen-age children and rummaged through the home, looking for valuables, police said. The plan misfired when one of the children managed to phone a relative before being discovered. Police, who surrounded the house and ordered the men to surrender, arrested Jorge Campusano, 25, of Inglewood, and Alvarado Solo, 25, of Los Angeles at the house. The third suspect, Donald Pearson, 36, of North Hollywood, was arrested four hours later by Downey police in Huntington Park.