Army troops captured another suspect in the Oct. 3 murder of the son of former Coahuila state Gov. Humberto Moreira, Mexico’s defense department said.

Carlos Arnulfo Flores was apprehended in Monclova, Coahuila, along with three associates who “assaulted the military personnel with gunshots,” the department said in a statement.

Flores, reputed to be a local boss of the Los Zetas drug cartel, was treated for minor injuries received during the exchange of fire.