Mexican army officials announced on Monday the arrest of a Zeta drug cartel member deemed responsible for the dumping 49 bodies along a highway in northern Mexico last week. Daniel de Jesus Elizondo Ramirez, known as “El Loco,” was captured by Mexican troops on Friday and was present at Monday’s press conference. According to a military spokesperson, Zeta bosses Miguel Angel Treviño Morales and Heriberto Lazcano ordered Elizondo Ramirez to leave the bodies in a town square in Cadereyta, though they were ultimately found in the town of San Juan, 18 miles (29 km) east of Monterrey on May 13.

Graffiti at the scene of the crime immediately made the Zetas likely suspects and authorities’ suspicions were confirmed when a banner was found near the bodies that read, “Gulf cartel, Sinaloa cartel, marines and soldiers, nobody can do anything against us or they will lose,” and was signed by Zeta leaders. In the days following the incident, signs appeared across northern Mexico claiming that the Zetas were not in fact responsible, but authorities did not take the bait. The 43 men and 6 women were found with heads, hands and feet cut off, making the identification process much more difficult for Mexican authorities.

Last week’s massacre was the third such atrocity this month in the “Triangle of Death”—the area between highways that connect Monterrey, Nuevo Leon, Reynosa and Nuevo Laredo that is ground zero of the war between cartels. Eighty percent of the 4,832 missing person cases between 2006 and 2011 occurred in that area.