The trial of a US Border Patrol agent turned alleged killer began in Texas Monday — with Juan David Ortiz facing charges of murdering four prostitutes and attempting to kill a fifth.

The murders took place in the Texas border city of Laredo in 2018. Prosecutors say the former Border Intelligence Supervisor admitted going on a 12-day killing spree in September of that year, according to an arrest affidavit.

Ortiz provided a “voluntary verbal confession” he shot and killed the four women, the affidavit reads. Ortiz is also accused of dumping his victim’s bodies in rural areas outside Laredo.

Prosecutors claim Ortiz told investigators he was “doing a service” by killing the women and that he didn’t think law enforcement was doing enough to curb prostitution.

On the first day of the trial, a fifth victim testified Ortiz had tried to kill her but she escaped. Erika Pena, who admitted to sleeping with men to support her drug habit, told the jury Ortiz picked her up on the street on Sept. 14, 2018 and took her to his house, while his wife and kids were out of town.

While riding in his pick-up truck, Ortiz threatened her with a gun, she testified.

When she tried to get out of his truck, he tried to stop her, ripping her shirt in the process and leaving her to run topless to a near-by gas station where she asked a state trooper for help.

Ortiz’s defense team fired back during their opening statements, claiming the disgraced agent’s confession was forced.

The 39-year-old is also accused of killing Guiselda Alicia Hernandez, 35; Claudine Anne Luera, 42; Melissa Ramirez, 29; and Nikki Enriquez, 28, a transgender woman.

Although Ortiz faces capital murder charges which could make him eligible for the death penalty, prosecutors are not seeking it at the request of the victim’s families, according to the San Antonio Express News.

“The families unanimously voted and requested that I remove the death penalty and seek life without parole,” Webb County District Attorney Isidro Alaniz, the lead prosecutor, told the paper.

“As one family member stated, ‘Getting the death penalty would be letting him off easy.’ Consequently, I granted their request and made the change in punishment.”

The killings received intense media attention in South Texas. Earlier this year, a judge granted a change of venue from the Laredo area to the San Antonio area to ensure an imparial jury. The trial is expected to be two weeks long and continues Tuesday.