The 10-year border patrol veteran killed at least four women throughout September, officials said during a Monday press conference, describing the suspect as a "serial killer". After believing he was identified, the 35-year-old began stockpiling weapons to prepare for a potential standoff with local police, investigators said.
Mr Ortiz "was going to try to commit suicide by cop," according to Webb County Sheriff’s Chief Deputy Federico Garza.
The chief deputy told reporters Mr Ortiz "took advantage of this community, he had the trust of most of his victims, and he took that opportunity to commit this crime".
"He knew that the victims were harmless, that they really didn't have a defence against him," he continued. "At this point, that’s all we know at this time."
Officials suggested the border patrol supervisor had a deep "hatred" for prostitutes, while alleging multiple of Mr Ortiz’s victims were part of the sex workers' community. Investigators are still working on discovering his motive and creating a historical outline of events to determine whether other killings had taken place.
Law enforcement has not released any of the victims’ names, however, one is believed to be a transgender woman, according to the Tampa Bay Times.
In an apparent planned attempt to kill himself, Mr Ortiz was going to brandish his cellphone to look like a weapon, according to Mr Garza. Instead, he was taken into custody this weekend in Laredo, Texas.
The border patrol supervisor was arrested early Saturday after a fifth victim escaped from Mr Ortiz and found a state trooper. The suspect fled and was found hiding in a truck in a hotel parking lot in Laredo, about 145 miles southwest of San Antonio.
Webb County District Attorney Isidro Alaniz told The Texas Tribune that after Mr Ortiz picked up the fifth woman she quickly realised that she was in danger.
“When she tried to escape from him at a gas station that’s when she ran into a (state) trooper,” he said.
He also said that authorities believe Mr Ortiz had killed all four women since 3 September. Mr Alaniz said two of them victims were US citizens, but the nationalities of the other two were not yet known.
"It’s interesting that he would be observing and watching as law enforcement was looking for the killer, that he would be reporting to work every day like normal," he continued.
— Janel Forte (@JanelKHOU) September 17, 2018
The suspect is being held on $2.5m bond on several charges, including four counts of murder. It is not clear whether he has been assigned a lawyer yet, or given a a chance to enter a plea.
On Monday, national border patrol chief Carla Provost was forced to defend the agency she just recently began overseeing in August.
Ms Provost said she was "sickened and saddened" by the allegations against Mr Ortiz, while adding, "I cannot imagine the impact this has had on the community".
She called border patrol agents “consummate professionals” and said one supervisor’s actions were “not indicative of my work force”.
“There has been no lowering of standards,” she added.
Customs and Border Protection issued a statement saying that it was fully cooperating with the investigation.
“Our sincerest condolences go out to the victims’ family and friends. 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..
The Texas Department of Public Safety, whose Texas Rangers are investigating, did not respond to enquiries.
The Associated Press contributed to this report.