MEXICO CITY (Reuters) - A Mexican journalist who often covered crime and drug gangs in northern Sonora state died late Friday night after being gunned down at point-blank range in his home near the U.S. border, local authorities said on Saturday.

Santiago Barroso was shot multiple times after an unknown assailant knocked on his front door, the state prosecutor’s office said in a statement. He was pronounced dead later at a hospital.

Barroso worked as a multimedia journalist in the border town of San Luis Rio Colorado, about 20 miles (32 km) southwest of Yuma, Arizona on the U.S. side. He was host of a local radio show, director of the news website Red 563 and a contributor to weekly newspaper Contraseña.

While it was unclear if his killing was linked to his work, Barroso’s death marks the third journalist killed so far this year in Mexico, one of the world’s most dangerous countries for reporters.

Alfonso Durazo, Mexico’s security minister, pledged federal government assistance in the investigation into Barroso’s killing in a post on Twitter.

According to free-speech advocacy group Article 19, at least 46 journalists have been killed in Mexico from 2012 through last year.