The Washington Post today announced its participation in “The Cartel Project,” a collaborative investigation coordinated by Forbidden Stories, an international network of investigative journalists whose mission is to continue the work of other journalists facing threats, imprisonment or murder. The investigation involves 25 organizations in 18 countries and will include five stories, the first of which will be published by The Post.

The Post’s investigation focuses on Regina Martinez, a journalist who was murdered in 2012 in the Mexican state of Veracruz. Her killing was part of a wave of violence against journalists in Mexico, where more than 90 percent of press freedom cases go unpunished. Since her death, more than 20 journalists have been murdered in Veracruz, which is now considered the most dangerous place in the world for journalists.

“As journalists, we have a responsibility to inform readers about what we learn through reporting. That is being challenged in many corners of the world and journalists are increasingly at risk for doing this important work,” said Jeff Leen, investigative editor at The Washington Post. “At this critical time for press freedom, we are pleased to be the United States partner for an important investigation that brings to light vital information about the dangerous task of being a journalist in Mexico.”

“The Cartel Project” will publish Dec. 6 at 12pm ET.