Two gunmen shot dead López, a reporter for the Guatemala City daily Prensa Libre, and Federico Salazar, a reporter for the Guatemala City station Radio Nuevo Mundo, while the journalists were walking in a park in Mazatenango, the capital of southwest Suchitepéquez department. A third journalist, Marvin Túnchez, a reporter for the local Canal 30 cable TV station, was also injured in the shooting. The gunmen fled on a motorcycle.
López had worked as a correspondent in Suchitepéquez for Prensa Libre for more than a decade and often wrote about corruption and the misuse of public funds, according to the paper. He had also compared corrupt politicians to mafia dons on his Twitter account, Prensa Libre reported.
According to the Guatemalan online investigative journalism outlet Plaza Pública which cited an official at the attorney general's unit for crimes against journalists who asked not to be identified, López called the official an hour before he was killed and told him he was frightened and that the environment in Mazatenango was "very charged." López told the official that his fear was related to his investigation into a story on money laundering in Suchitepéquez, according to Plaza Pública.
Miguel Angel Méndez Zetina, editor of Prensa Libre, said that the journalist "received constant threats by municipal authorities for his stories about government corruption," according to the paper. In 2013, López was publicly threatened by a public official after the journalist published a story about public works projects in the town, according to the Guatemalan press freedom group CERIGUA.
In an interview conducted in early 2014 but published after his death, López said that members of organized crime had infiltrated the local government and law enforcement. "No one trusts the police," he said. "This makes the justice system very weak ... because there are groups occupying space in the public life."
In an interview after the attack, Túnchez told the Guatemalan daily Publinews that the gunmen "approached Danilo directly. The attack was against him. Federico and I were collateral victims."
In the days after the murder, authorities arrested two men they said were suspected of being the gunmen, according to news reports.
Federal authorities said shortly after the attack that they were investigating the possible involvement of an organized crime network working in the area with links to the Mexican drug trafficking group, the Sinoloa Cartel, according to news reports. Authorities requested that the investigation be transferred to a special court in the capital dedicated to high risk cases after local prosecutors investigating the crime received threats, according to the reports.
In June 2015, authorities arrested two police officers and a third man suspected of forming part of the criminal network that is suspected of being involved in the crime. In November 2015, prosecutors accused three members of the Public Ministry and two lawyers of leaking confidential information about criminal cases, including the investigation into the journalists' murder, to criminal groups. No one had been charged by mid-December 2015.
López is survived by his wife, who was pregnant when he died, and a daughter.