The county's district attorney, Isidro Alaniz, says authorities were led to Ortiz after a woman he tried to kidnap escaped from him.
A border agent was arrested early Saturday in South Texas by officials searching for a serial killer in the Laredo area.More news: Browns finally reach end of rope, will cut Josh Gordon
Officials say they were alerted about the 35-year-old Ortiz after a fifth woman allegedly escaped from him and notified authorities. State troopers found Ortiz hiding in a truck in a hotel parking lot in Laredo at around 2 a.m. Saturday.
The names of the victims were not released but Alaniz says two are USA citizens. Alaniz also said the male victim was believed to be a prostitute.
He said that authorities believe Ortiz had killed all four women since September 3. Two of the victims were found earlier this month along Interstate 35 in rural northwest Webb County, the Laredo Morning Times reports.More news: 'PREPARE TO DIE': Leftists' Heads Explode Over Trump Alert
Sheriff Cuellar told reporters that Agent Ortiz is a 10-year veteran supervisor of the Border Patrol. Cuellar said investigators believe Ortiz acted alone. "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", the agency said.
Webb County Sheriff Martin Cuellar said in a statement: "We feel that our efforts have gathered strong evidence against this killer".
"I extend my condolences to the families of the victims during this hard time".More news: North Carolina coast feels Florence's first blast of wind, rain
Alaniz said his office plans to charge Ortiz with four counts of murder and one count of aggravated kidnapping. But the spokesperson referred all other questions to authorities in Webb County and the Texas Department of Public Safety.