A US Border Patrol agent has been arrested and confessed to the murders of four people in the town of Laredo, Texas, near the Mexican border.

Juan David Ortiz, 35, was arrested on Saturday and charged with four murders and one unlawful restraint with aggravated assault with a deadly weapon.

CNN reports that the U.S. Customs and Border Protection agent was arrested when a fifth victim escaped an attempted kidnapping. Webb County District Attorney Isidro Alaniz says that the victims were all females and worked as prostitutes. They were all shot in the head and killed between September 3 and September 15.

Authorities became aware of Ortiz’s activities on Friday when a fifth woman escaped his grasp. Speaking with police, the unnamed woman said she was in a truck with a man named “David”. Ortiz reportedly pulled out a gun and pointed it at the woman but she managed to flee and find a state trooper at a nearby gas station. After describing Ortiz, police tracked him down at near a gas station in Laredo, Texas, where he was hiding in the bed of a pickup truck.

In a statement, a US Customers and Border Protection spokesperson said the agency is cooperating with authorities.

“While it is CBP policy to not comment on the details of an ongoing investigation, criminal action by our employees is not, and will not be tolerated.

“Out of respect for the victims’ family and friends, we ask that deference and due process be given to the investigation so that all the facts are brought to light and they can receive the closure they deserve.”