Maynor Mena, the local police chief, told the news media the attack was a personal vendetta. The assailants were described as about 30 unknown persons, who pulled up to the pool hall in several vehicles. After killing six people who had been playing pool, the attackers entered an adjacent apartment, where they killed a 15-year-old child. They also threw a grenade into the pool hall, but it failed to explode.
Police suspect the crime was part of a rival gang fight for territory.