Extortion believed to be the motive behind  July shooting

Multiple charges, including extortion, assault and the use of a firearm, have been filed in connection with a July 12 shooting, according to Waltham police. According to a report, police responded to a medical emergency on Lexington Street at around 1 p.m., where they found a man with a gunshot wound and a knife stuck in his shirt.

After the man received medical care, he told police that a man unknown to him had entered his vehicle and shot and stabbed him before fleeing, according to the report.

According to the police report, after further questioning, the victim eventually changed his story, saying he was attacked after attempting to meet up with a female acquaintance he called “Selena.”

The real story

The victim knew Selena as a former neighbor. He was reluctant to tell the real story as he was scared that his partner would find out he was texting another woman.

According to police records, the victim told investigators that Selena owed him $200, and he had been trying to get it back. The victim had previously lent Selena money because she told him she was struggling financially.

The victim had agreed over WhatsApp to pick up the money at Selena’s residence on July 12. She said a man would be waiting there to collect the money, who would also need a ride to the liquor store.

The victim picked up the man and drove him to a location on Warren Avenue as per his instructions. Once the vehicle was stopped, the passenger told the victim that he wanted money from him and had been paid to kill him. When the victim refused to hand over the money, the passenger shot and stabbed him before fleeing, according to police.

Police collected physical and forensic evidence from the crime scene, including 9 mm shell casings and a knife wrapped in a blue t-shirt that were found in the car, but the WhatsApp messages the victim referenced were shown to have been deleted by Selena.

Usage Secret Service technology

To recover these messages, the Police Department enlisted help from a Waltham police detective, who is a member of the Cyber Fraud Taskforce with the United States Secret Service. 

The task force provided investigators with a device called a DataPilot to locate the messages.

The device was not able to recover the contents of the messages, but instead found more examples of messages that were deleted by Selena.

The victim provided Selena’s phone number and investigators ran it through their database, finding a match for Gaby Sandoval-Matute, 31, of 83 Lexington St., Waltham.

Detectives also sent the victim’s mobile phone to the United States Secret Service’s Evidence Forensic Lab in Boston for further extraction.

Closing in

Investigators were able to find Ring camera footage from the night of the attack from a Warren Street residence. The footage showed a man matching the description provided by the victim walking down the roadway.

The owner of Sandoval-Matute’s apartment said that Gaby sometimes went by Selena and lived at the address with her two daughters and her boyfriend, whom she knew as Gustavo Murillo. The owner shared that the two had missed around $4,000 to $5,000 in rent payments and that Murillo told Sandoval-Matute that he would help pay for the rent that week.

When investigators ran Murillo’s name through the Interstate Identification Index, they discovered that a man named Justo “Gustavo” Murillo-Sanchez, 37, had been sentenced for aggravated robbery in Houston, Texas, but was released in 2017.

Investigators showed a picture of Murillo-Sanchez to the building owner, who said it looked like the man she knew as Matute-Sandoval’s boyfriend.

According to police, investigators searched Sandoval-Matute’s residence on July 19 and found a shirt resembling the one the suspect wore in the Ring camera footage with small red stains on it, a black hooded mask and financial documents with both Sandoval-Matute’s and Murillo-Sanchez’s names on them.

When asked to clarify the nature of his relationship with the woman, the victim told investigators that he sometimes gave her rides and sent her money, police said.

During one exchange, the victim intended to send his brother in Guatemala $6,000, but could only send half himself due to wire transfer limits. He had Sandoval-Matute wire his other $3,000 to his brother. This event led investigators to believe that Sandoval-Matute knew the victim had access to thousands of dollars.

The alleged motive

Because investigators knew Sandoval-Matute was behind on rent, investigators believed she attempted to extort the victim using Murillo-Sanchez to threaten him. As numerous WhatsApp messages were deleted, investigators also believed Sandoval-Matute tampered with evidence by erasing messages between her and the victim.

Charges filed

The report does not detail when Sandoval-Matute and Murillo-Sanchez were detained, but court records show that they appeared for their arraignments at Waltham District Court on July 24.

Sandoval-Matute pleaded not guilty to withholding evidence from a criminal proceeding, conspiracy, assault and battery with a firearm and two counts of assault and battery with a dangerous weapon. She awaits her Aug. 28 probable cause hearing from the Middlesex Correctional Institute in Framingham.

Murillo-Sanchez pleaded not guilty to assault and battery with a firearm, extortion by threat of injury and three counts of assault with a dangerous weapon. He awaits his Aug. 28 probable cause hearing from the Middlesex Jail.

A spokesperson for the Waltham Police Department shared that this case is still an open investigation, so those involved could still receive additional charges as the case continues.

All information for this story was gathered from official court documents found at the Waltham District Court and case information from masscourts.org.