An Alameda County sheriff's deputy faces two counts of murder as well as several special allegations and the prospect of death-penalty consideration in connection with the brutal slayings of a couple in their Dublin house early Wednesday morning.

Documents filed with the court by prosecutors on Friday morning include new details about the scene and circumstances of the double homicide in the neighborhood in East Dublin, including descriptions of kill shots to the victims' heads and necks and the contention from the suspect's family that he had been involved in a romantic relationship with the married female victim.

"Our hearts and condolences go out to the family, friends and community of the two victims killed in this incident," Alameda County District Attorney Nancy O'Malley said in a statement after her office submitted the criminal complaint.

Devin Williams Jr., 24, of Stockton was scheduled to be arraigned in Alameda County Superior Court in Dublin later Friday. It was not immediately clear if he is yet represented by an attorney.

Williams, a sheriff's deputy of one year who is now in the process of being fired after his arrest, has been charged with two counts of first-degree murder for the shooting deaths of 42-year-old Maria Tran and her husband Benison Tran, 57.

The defendant also faces special allegations related to gun use and great bodily injury inflicted on both victims, as well as special circumstances for multiple murders and murder to avoid arrest. Special circumstances murders are eligible for the death penalty, though a decision about whether to pursue a capital case are typically made after the preliminary hearing.

The violent scene inside the Colebrook Lane house, just off Fallon Road, and the investigative aftermath were described in a probable cause declaration written by Officer Riley Walter of Dublin Police Services, filed with the court as justification for Williams' arrest.

Police received a call from people in the home at 12:45 a.m. Wednesday reporting someone inside and then shots being fired, according to Walter.

"The reporting party called 911, and someone they did not know was inside their residence. One of the residents picked up the phone and advised the suspect was armed with a firearm, and the suspect shot his sister and his brother-in-law. The reporting party advised the suspect left the scene in a vehicle," Walter wrote.

Officers arrived to find a husband and wife – later identified as the Trans – with gunshot wounds to their heads and necks. Both were pronounced dead by paramedics shortly after, according to Walter.

Multiple family members were present during the shooting. "When deputies arrived, they heard an unknown family member say, 'Devin' and 'He is a cop,' according to Walter.

Sheriff's Lt. Ray Kelly previously confirmed that the couple's 14-year-old child, as well as Maria Tran's mother and brother were in the house that night.

Dublin Police Services, which is the lead investigative agency in the case, is staffed by deputies of the Alameda County Sheriff's Office under the city of Dublin's contract with the county to provide police services. Williams worked for the sheriff's office and was assigned to the courthouse and jail operations, not a patrol beat. He was reported to be off-duty as of 11 p.m. Tuesday.

During their subsequent investigation, officers spoke with Williams' family and his father told detectives that Williams "had been in a dating relationship with the female victim (Maria Tran) and had been to their residence in Stockton," Walter said. The circumstances of that apparent relationship were not immediately clear.

In the wake of the discovery on Colebrook Lane, detectives reviewed license plate reader camera data from the neighborhood and observed a gray Volkswagen Jetta registered to Williams driving near the crime scene one minute after the shooting, according to Walter.

Additionally, detectives allegedly found six shell casings with "Speer 9mm" inscribed on them – the same type of ammunition used by the sheriff's office. Kelly previously reported investigators believed Williams likely used his department-issued service weapon during the crime and discarded it in the Altamont Pass area outside of Livermore while fleeing.

According to Walter, detectives later created a photo lineup and two separate witnesses identified Deputy Williams as the shooter. The 24-year-old remained on the lam for nearly 12 hours Wednesday.

Walter confirmed Williams was arrested near Coalinga, some 147 miles from the crime scene, after surrendering without further incident to the California Highway Patrol in the same Volkswagen seen by the license plate camera. Kelly reported Williams called DPS headquarters just after 11 a.m. and spoke with Police Chief Garrett Holmes for more than 45 minutes before agreeing to pull over and give himself up peacefully.

"Williams' issued duty weapon box, and some of his safety gear, including Speer ammunition, was inside his car. Red matter believed to be blood was also inside the vehicle," according to Walter.

The suspect did not speak with investigators after his arrest, invoking his constitutional right to remain silent, according to Walter.

He was booked Wednesday evening into the Santa Rita Jail in Dublin – where he had worked an overtime shift that ended less than two hours before the shooting. Kelly said Williams was served with notice of his pending release from sheriff's office employment after his arrest.

Williams is expected to enter a plea to the charges during a court appearance in the coming days.

The court documents filed Friday did not elaborate further on the reported "dating relationship" between Williams and Maria Tran.

Maria Tran was a registered nurse, according to online records. Benison Tran's employment has not yet been confirmed. The Trans' trust purchased the house on Colebrook Lane about a year and a half ago, according to Tri-Valley home sales data reported by the Pleasanton Weekly in spring 2021.

This marked the first homicide (non-vehicular) in the city of Dublin since November 2020 and the first time a deputy has been accused of a murder occurring while employed by the sheriff's office since the infamous Eric Wright case – that being an arrest in 2002 for a killing that took place in 1980, just before then-Lt. Wright vanished mysteriously for two-plus decades. Wright ultimately pleaded guilty to manslaughter.