A U.S. Border Patrol agent has been arrested on suspicion of killing four women and abducting a fifth, who managed to escape.

According to the Associated Press, Juan David Ortiz—an intel supervisor for the Border Patrol—was captured by Texas authorities early Saturday after he was found hiding in a hotel parking lot in Laredo. Law enforcement said there is “very strong evidence” that Ortiz murdered four women who worked as prostitutes.

Investigators said they are still trying to determine a motive. They did not reveal any details about the case, such as the evidence against Ortiz, the victims’ names and nationalities, or the ways the women were murdered.

Webb County district attorney, Isidro Alaniz, described Ortiz as a “serial killer.” He also announced the office intends to charge the agent with four counts of murder and one count of aggravated kidnapping.

Stay tuned as more information about the case becomes available.