On March 28, police arrested two of Mora's neighbors, Mario Medina Vázquez and Hiram Olivero Ortiz. Police said Medina confessed to killing Mora in a crime of passion, but Medina later recanted and said he confessed under torture. On May 13, Medina was stabbed to death in a Nueva Laredo prison.
An commission of press organizations and human rights groups, created after Mora was killed, said that the initial investigation was marked by errors and asked authorities to conduct a thorough and impartial inquiry.
Although Mora had not received any threats, many of his colleagues believe that the murder may be related to El Mañana's coverage of drug trafficking and corruption in Nuevo Laredo. The city, located on the U.S.-Mexico border, is notorious for its drug gangs and is plagued by violence.