An unidentified assailant shot Gómez, 70, as he returned home with his wife, and then fled on a motorcycle, news reports said.
Gómez, a freelance journalist and a government witness in an investigation into links between politicians and paramilitary groups, had reported on local corruption in the Urabá region of Antioquia, according to the Colombian press freedom group Foundation for Press Freedom. Most recently, he had written about tourism and the environment for the local newspapers El Heraldo de Urabá and Urabá al día, among others. The newspaper El Colombiano said the journalist had not received any threats prior to his death.
Gómez was also participating as a witness in the attorney general's investigation into links between politicians and illegal right-wing paramilitary groups, a case commonly known as the "parapolitics" scandal. Another witness in the case was killed a few days before the journalist's death, and investigators said other witnesses had disappeared, press reports said.
Gómez was also investigating the unsolved murder of his son two years earlier, the daily El Espectador said.
Until 2006, the violent Urabá region of Antioquia province had been controlled for many years by the paramilitary group United Self-Defense Forces of Colombia, press reports said. Colombian provincial journalists, working in areas where paramilitaries and other illegal armed groups had been prevalent, faced severe challenges in reporting on the organizations' activities, CPJ research shows.