A Mexican government panel charged with protecting journalists has failed to investigate more than half of the complaints of assaults or threats against journalists

Of the 152 cases reported to Mexico’s Federal Mechanism for the Protection of Human Rights Defenders and Journalists since 2012, only 64 have been investigated, the Mexican publication Animal Politico reported, citing members of the panel.

Established in 2012 and modeled after a similar program in Colombia, the mechanism is was intended as a means for at-risk journalists to request prevention before they become victims of violence. It quickly garnered criticism from members of the press who found it ineffective.

The news comes six weeks after the body of abducted journalist Gregorio Jiménez de la Cruz was found in Veracruz state. At least three journalists were killed in the country in 2013, according to the Committee to Protect Journalists.

Others have been forced into exile, including investigative journalist Verónica Basurto Gamero, who fled the country in 2013. In May, she criticized the Federal Mechanism’s failure to provide adequate protection for her or her family despite her reports of threats made against her, according to Reporters Without Borders.

The revelation about the uninvestigated cases came 10 days after Juan Carlos Gutiérrez Contreras, the head of the Federal Mechanism, resigned from his position, Animal Politico said.