Savanah Soto murder: Third suspect arrested, believed to be step-mother of another suspect

The San Antonio Police Department has announced a third arrest of a suspect in the deaths of Savanah Soto and her boyfriend, Matthew Guerra. 

Myrta Romanos was arrested on Wednesday on three felony charges related to the murder of 18-year-old Soto and Guerra including destroying or concealing a human corpse, abuse of corpse, and tampering with evidence.

Romanos was seen on video the night of the murder leaving in the black truck seen in surveillance video released by police and returning to the home with 19-year-old Christopher Preciado Christopher and 53-year-old Ramon Preciado in the truck.

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Christopher and Ramon were arrested and charged for their roles in the murders on Jan. 3. Christopher was charged with capital murder for the two deaths and Ramon was charged with abuse of a corpse for helping Christopher move the bodies after they were killed.

Authorities added the charges of altering, destroying, or concealing evidence for both Christopher and Ramon and also charged Christopher with abuse of a corpse.

On Dec. 26, Soto and Guerra were found dead in a 2013 Kia Optima at the Colinas at Medical Apartments in San Antonio. Soto was nine months pregnant, her family confirmed.

The Bexar County Medical Examiner's Office said that Savanah's cause of death was a gunshot wound to the head and her death was a homicide. They also said Guerra's death was a contact wound to the head and the manner of death is also being ruled a homicide.

Myrta Romanos (Courtesy of San Antonio Police Department)

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San Antonio Police Chief William McManus said detectives searched the Preciados’ home and found a gun "believed to be the murder weapon."

According to SAPD, Romanos confirmed it was her gun which also matched the ballistics used in the deaths.

Police say they are unsure of Romanos' role but believe she was involved in helping get rid of the evidence concerning the bodies.