More than 200 federal, state and local law enforcement personnel have been assigned to an operation intended to find who was responsible for Saturday's fatal shootings of three people linked to the U.S. consulate in Cuidad Juarez, Mexico, an official said.

Among the agencies involved in Operation Knock Down -- taking place in southern New Mexico and in the vicinity of El Paso, Texas -- are the FBI and the Drug Enforcement Administration, said DEA spokesman David Ausiello.

El Paso is across the Rio Grande from Ciudad Juarez.

A law enforcement official said investigators believe that there could be a connection between Barrio Azteca, a gang that operates in both cities, and the killings. The official said that mistaken identity has not been ruled out.

A relative of U.S. consulate worker Lesley Ann Enriquez said Wednesday that the 35-year-old woman was four months pregnant with a boy when she was shot dead. Enriquez's husband, 34-year-old Arthur Redelfs, was also killed. He was a 10-year veteran of the El Paso County Sheriff's Office.

The couple was fired on in their SUV as they left a birthday party at the U.S. consulate. Their 7-month-old daughter, Rebecca, who was in the back of the SUV, was unhurt.

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