SAN ANTONIO — Over the course of 12 days in the fall of 2018, the bodies of three women who had been shot in the head began appearing along roadsides in the border city of Laredo, Texas.
After an intense manhunt, the police caught a break when a woman working as a prostitute told the authorities that a client had pulled a gun on her, and that she had barely managed to escape. Her account was shocking for another reason: The man she identified, Juan David Ortiz, was a supervisory intelligence officer with the U.S. Border Patrol, whose officers are ubiquitous in southern border towns like Laredo.
On Thursday, at Mr. Ortiz’s trial on capital murder charges in San Antonio, prosecutors played to jurors large portions of a recorded video interview in which he appeared to admit to the killings, at times crying and resting his face on a table.
“I was continuing driving on San Bernardo, and then this is when the monster came out,” Mr. Ortiz can be heard saying in the video, referring to the avenue where he picked up the prostitutes.
Mr. Ortiz has since denied responsibility for the killings and claimed that the confession was coerced.
A Border Patrol agent convicted of serial murder would be the latest case — and one of the worst — of criminal misconduct identified in recent years by the Border Patrol, whose more than 19,000 agents patrol vast and often remote areas of the U.S. frontier that are prone to human trafficking, drug smuggling and other criminal operations.
Just five months before Mr. Ortiz’s arrest, another Border Patrol supervisor in Laredo, Ronald Anthony Burgos Aviles, was arrested and charged with killing a woman with whom he was romantically involved and her year-old son. That case is pending.
Border Patrol officials declined to comment on the Laredo case but have said that a majority of its agents conduct their duties with integrity and professionalism, and that cases of misconduct are pursued “decisively.”
Mr. Ortiz, a married father of three children, faces up to life in prison if convicted on charges of capital murder, aggravated assault, unlawful restraint and evading arrest.
In the trial that began this week, prosecutors said the victims in the case were all prostitutes working along San Bernardo Avenue, a notorious red-light district, who were picked up and taken to secluded areas, where they were shot in the back of the head.
The Webb County district attorney, Isidro Alaniz, told the jury that the victims — Melissa Ramirez, Claudine Anne Luera, Guiselda Alicia Cantu and Janelle Ortiz — were mothers, daughters and sisters with families who loved them.
He said the prosecution would present a trove of forensic evidence as well as a nine-hour videotaped confession to prove that Mr. Ortiz committed the crimes.
“The case is about a man who betrayed his badge,” Mr. Alaniz told the jury. “He betrayed his country. He betrayed his family. He betrayed his community, for his own selfish needs.”
But Joel Perez, addressing the jury for the defense, said Mr. Ortiz was not a killer but a dedicated law enforcement officer who had been erroneously identified by a woman who was under duress. At the time of his arrest, he said, Mr. Ortiz was suffering from a series of mental health problems, including depression and anxiety, and, during his purported confession, he had merely regurgitated what he had read in newspapers, in an effort to end an interrogation that had lasted for more than nine hours.
“This is a defeated man,” he said.
Mr. Ortiz, 39, wearing a black suit, gray shirt and burgundy tie, looked visibly rattled, and at times he took off his eyeglasses and shook his head as prosecutors and witnesses painted him as a predator who had targeted vulnerable victims at the margins of society.
Erika Peña, the woman who had identified Mr. Ortiz to the police, described in detail how she had escaped an attack at gunpoint.
Ms. Peña, who said she had known Mr. Ortiz for about five months, told the jury that she had recognized his white pickup truck and had felt comfortable riding in it to his home, knowing that Mr. Ortiz’s wife and children were out of town.
Once there, she said, the two engaged in friendly small talk. But the mood turned tense, she said, when she brought up the recent death of one of her friends, Ms. Ramirez, a fellow prostitute who had been found dead on a dirt road days earlier.
She said Mr. Ortiz told her that he was afraid the police might find his DNA during its investigation of that case because he had picked Ms. Ramirez up recently. At that moment, Ms. Peña told the jury, she grew suspicious. “David was not himself anymore,” she said. “I was scared.”
She ran out of the house and vomited, she testified. “I just got this feeling that he was the one that had been murdering,” she said, her voice breaking at times.
Still, she tried to regain her composure and asked Mr. Ortiz to take her out to get food, part of what she said was an effort to get out of his house. Mr. Ortiz agreed and drove her to a gas station, where he parked in the back, according to her testimony.
Seemingly without warning, she said, he pointed a gun at her head with his left arm and grabbed her blouse with the other.
At that point, she said, her adrenaline kicked in and she managed to open the door of the passenger side and wrestle herself out of her blouse. “Someway, somehow, I took off running without a shirt,” she said. “Everything happened so fast.”
She said she had run up to a Texas state trooper who had been pumping gas and had told him that she was fearful for her life. The trooper, who recorded the encounter with his body-worn camera, told her that he believed her and that she was now safe.
Ms. Peña’s account was the first important break for the police since the first body had been discovered 11 days earlier, on Sept. 3, 2018, prosecutors said. She directed the police to Mr. Ortiz’s house, and they obtained a warrant for his arrest.
Mr. Ortiz had given no indication that he was a danger to others before that time, officials said. He had joined the U.S. Navy two months before the attacks of Sept. 11, 2001, and had served for eight years. He told investigators that he had served time in Iraq.
After leaving the Navy in May 2009, Mr. Ortiz began working for the Border Patrol, where he quickly climbed the ranks to become a supervisor in an intelligence division. While an agent, he earned a master’s degree from St. Mary’s University in San Antonio and spent his entire career within the Laredo sector, which encompasses more than 100,000 square miles, stretching from the border region in South Texas north to the Texas-Oklahoma line.
The jury saw dramatic police camera footage that showed the moment heavily armed officers arrested Mr. Ortiz in a motel parking lot, several hours after Ms. Peña’s report and after he had initially run away from officers seeking to question him.
Mr. Alaniz, the lead prosecutor, said Mr. Ortiz had been provided with water, food and bathroom breaks during his questioning by the police. “Law enforcement treats Juan David Ortiz with nothing but dignity and respect,” Mr. Alaniz said.
He told the jury that Mr. Ortiz had initially denied involvement in the killings and then confessed.
“I wanted to clean up the streets’,” he told the police, according to a summary of the interview that Mr. Alaniz presented to the jury during opening statements. “These people,” he said, quoting the defendant, “are dirt, and I was going to get rid of them. Law enforcement doesn’t do anything about them? I will. I’m sick of them.”
After admitting that he had killed three of the women, Mr. Alaniz said, Mr. Ortiz alerted investigators to a fourth victim, Janelle Ortiz, whose body had not yet been discovered. “There is one more you all don’t know about,” Mr. Alaniz said, again summarizing the interview. “That’s the whole story.”
The body of Ms. Ortiz, a 28-year-old transgender woman, was found next to a mound of gravel near an interstate highway.
The case is expected to last another week.