Heriberto Lazcano Lazcano, the top boss of the Los Zetas drug cartel, may have been killed in a shootout with marines in the northern Mexican state of Coahuila, the Navy Secretariat said.

Forensic tests are being performed on the bodies of two suspected criminals killed in the gunfight with marines and there are “indications that one of the bodies is that of Heriberto Lazcano Lazcano,” the secretariat said in a statement.

Lazcano, known as “El Lazca,” deserted from the Mexican army in 1999 and formed Los Zetas with three other soldiers, all members of an elite special operations unit.