A Border Patrol agent who allegedly murdered four women involved in sex work in a disturbing attempt to “clean up the streets” of Laredo, Texas pleaded not guilty in court Thursday afternoon, the Laredo Morning Times reports. Juan David Ortiz was arrested in September, and police said he admitted to killing four sex workers by shooting them in the head over 12 days. Another woman reportedly fled from him before he could harm her and alerted authorities, leading to his arrest. Prosecutors, who described him as a serial killer, later said he told investigators he targeted the women because he thought he was “cleaning up the streets” by doing so. Judge Oscar J. Hale Jr. set his pretrial hearing for April 25, and a second hearing for Oct. 3 in court on Thursday. The mother of one of Ortiz’s victims reportedly yelled out, “maldito asesino!” while Ortiz exited the courtroom. “Maldito” reportedly means “evil person,” and “asesino” means “assassin.” Ortiz was indicted in December on “one count of capital murder, aggravated assault with a deadly weapon, unlawful restraint and evading arrest.” Ortiz is currently being held on a $2.5 million bond, and prosecutors are seeking the death penalty.