LAREDO, Texas — The Border Patrol agent who was arrested in September for the murder of four women in Webb County pleaded not guilty Thursday at an arraignment hearing at the Webb County DA's Office.

Juan David Ortiz is facing four counts of murder, aggravated assault with a deadly weapon and unlawful restraint. 

According to affidavits , the 35-year-old Ortiz has "provided a voluntary verbal confession" in the deaths of the women. 

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Ortiz was arrested by state troopers on September 15 in Laredo after a series of murders that occurred in the span of two weeks.

The Webb County District Attorney described Ortiz’s motive as a “vigilante,” and “seeking to clean up the streets” of Laredo by randomly targeting a community associated with drugs and prostitution.

Melissa Ramirez, Claudine Luera, Guiselda Cantu and Humberto “Janelle” Ortiz are the victims in the case.

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No trial date has been announced yet. A pre-trial hearing will be held on April 25.