Investigation into deadly kidnapping of Americans in Mexico continues after cartel issues apology letter and hands over members

A week after the violent kidnappings of four Americans in Mexico, investigators are still working to piece together how and why the abduction unfolded, even after a cartel apologized for carrying out what one victim’s father has called “a senseless crime” that left two Americans and one Mexican woman dead.

The case remains “very confusing” to investigators, who are still obtaining information on the kidnapping last Friday and considering all angles, a Tamaulipas Prosecutor’s Office official familiar with the investigation told CNN.

Though authorities have not publicly named any suspects, an apology letter was issued Thursday by the Gulf Cartel, which is believed to be responsible for the kidnappings, and the group handed over five of its members to local authorities, according to images circulating online and a version of the letter obtained by CNN from an official familiar with the ongoing investigation.

CNN cannot confirm the authenticity of the photos and has asked Mexican and US authorities for comment.

“The [Gulf Cartel] apologizes to the society of Matamoros, the relatives of Ms. Areli, and the affected American people and families,” reads the handwritten letter, referring to a Mexican woman who was also killed by a stray bullet in the shootout.