A group of U.S. tourists, including a former Marine, killed a Costa Rican mugger by breaking his neck after he pulled a gun on them in a Caribbean port, a local police official said on Thursday.

The cruise ship passengers told police they jumped on Wagner Segura, 20, to defend themselves when he pointed a .38 caliber revolver at them near the Caribbean port of Limon on Wednesday, and somehow snapped his neck, regional police director Luis Hernandez said.

Segura died instantly and two other unidentified thieves, one of whom was armed with a knife, fled the scene, Hernandez said.

“One of the tourists was a former Marine and he was probably the one who broke (Segura’s) neck,” Hernandez said. “His neck was completely snapped.”

No charges will be filed against the tourists because police viewed the incident as an act of self-defense. Police questioned and released the group, which rejoined the cruise and left Cost Rica.

The Americans were passengers aboard the Carnival cruise ship Legend. They got off their tour bus to take photos in a notoriously rough neighborhood a short drive from Limon.

After the attack, they put Segura’s body on their bus and found a police officer in Limon to report the incident.