Tijuana – The federal police commander killed Friday in Tijuana was shot at least 22 times, according to information revealed Monday.

The commander, Guillermo Plata Camacho, 50, was attacked by gunmen on Aeropuerto Boulevard, in the Otay district, according to state authorities.

Attacks on federal commanders or officers are rare in the region. The federal Attorney General's Office immediately took over the investigation of Plata's murder but has not announced details publicly, according to the agency's press office.

Plata, who was born in Cuernavaca, in Morelos state, had worked for 25 years in the agency known in Mexico as the Federal Preventive Police. He headed the agency's station in the town of San Quintín, south of Ensenada.

In the last two years, San Quintín and the area of Ojos Negros have seen a significant increase in the number of marijuana crops grown in the mountains, agricultural valleys, ranches and communal farms.

A source in the federal Attorney General's Office, familiar with the investigation but not authorized to speak publicly, said that the commander was doing a customs transaction in the area near Tijuana's airport when he was ambushed.

"The way he was killed suggests that it's related to drug trafficking. It appears that they were following him and knew where he was going to stop," the source said.

The commander was shot around 11 a.m. Friday; his body was found outside of the patrol car he was driving. Investigators found eleven 9 mm shells and eleven 40 mm shells.

Federal officers and investigators are an elite group who support state and local police departments and the military. Since 2008, they have been primarily focused on drug-related organized crime.

Five members of federal police have been killed in Baja California since 2006, two of them commanders.

By contrast, attacks on state and municipal officers have become common. A total of 43 officers from Tijuana's Public Safety Department have been killed since 2007.

Since Friday, authorities have carried out a series of sweeps, mainly in the housing complex known as Módulos de Otay, about five minutes from the Otay Mesa border crossing, a known gathering place for gangs infiltrated by organized crime.

And over the weekend, federal officers patrolled some of the most heavily traveled avenues in the city's south and east sides, stopping drivers that seemed suspicious. There's been no official word of the results of these stops.

Omar.millan@sandiegored.com