San Diego police officers on Tuesday were searching for a gunman who entered a San Ysidro currency exchange house, identified himself as a police officer inspecting burglary alarm systems, then made off with $13,027 in U.S. currency and more than 1.43 million pesos valued at approximately $7,150. Bill Robinson, a Police Department spokesman, said the robbery occurred about 6:15 p.m. Monday at Northside Currency Exchange on San Ysidro Boulevard. The man showed two female employees a Police Department business card with the name of a former officer on it. The employees allowed the man behind the counter after he asked to make a telephone call. The thief then produced a small revolver and ordered the women to lie on the floor, Robinson said. He fired one shot into the floor and fired another shot into the air as he was leaving.