CAMPO, Calif. — A registered sex offender, who was a former officer with the Los Angeles Police Department officer, has been arrested on suspicion of human smuggling and possession of a “ghost gun” Monday near the U.S.-Mexico border, authorities said.

Around 9:55 p.m., San Diego Sector Border Patrol agents received a report about human smuggling involving an older model SUV occurring in Campo near the border, Eric Lavergne with the U.S. Customs and Border Protection said in a news release Friday.

Authorities were able to pull over a vehicle that matched the report. When the agent approached the vehicle, the driver, who identified himself as a lieutenant with LAPD, handed the agent a badge that looked similar to one from the department, border officials said.

An immigration inspection was conducted after the border agent noticed four people, three women and one man, in the back seat of the SUV, per CBP.

All four individuals admitted to recently crossing the U.S.-Mexico border illegally, prompting the agent to arrest the driver and passengers, according to officials. They were taken to a nearby Border Patrol station for processing.

Authorities found an un-serialized 9mm hand, also known as a “ghost gun,” in the suspect vehicle, as well as two fully loaded 9mm magazines and a shoulder holster.

“Record checks revealed that the driver is a former Los Angeles Police Department officer who separated from service in 1993, the same year he was convicted for forceful rape, a crime for which he was sentenced to three years in prison,” Lavergne said.

The driver, firearm and vehicle were turned over to the San Diego County Sheriff’s Department.