A border police officer was arrested on Saturday after allegedly killing four women believed to be prostitutes and kidnapping one-fifth, officials say.
Juan David Ortiz, an Intel border patrol supervisor, was found at about 2:00 am when state soldiers pursued him on a hotel car park in the border town of Laredo, Texas. He was found hiding in a truck.
Officials say they have been alerted about 35-year-old Ortiz after a fifth woman reportedly escaped and notified the authorities.
Despite withholding information about the killings, including victims' identities, Webb County sheriff Martin Cuellar said the investigators have "very strong evidence" that Ortiz is responsible for the deaths of the four women. Cuellar said the investigators believe he is acting alone.
Webb District Attorney Isidro Alaniz said the evidence indicates that "the way in which they were killed is similar". He said the authorities are still trying to find a motive for the killings, but that all women work as prostitutes.
"We consider this a serial killer," he said.
In a statement, Andrew Meehan, Deputy Commissioner for Public Affairs for US Customs and Border Protection, said his agency cooperates with all investigators.
"Our sincere condolences go out to the families and friends of the victims, and while CBP policy is not to comment on the details of an ongoing investigation, our employees' criminal activities are not tolerated and not tolerated," Meehan said.
The prosecution intends to charge Ortiz with four charges of murder and charges of serious kidnapping.
The Associated Press contributed to this report.