Key Points
- Police arrested 41-year-old licensed social worker Sosa Samura in connection with a fatal multi-vehicle crash in Cambridge.
- Prosecutors charged Samura with motor vehicle homicide while operating under the influence, second-offense OUI, OUI causing serious bodily injury, assault and battery with a dangerous weapon, leaving the scene of property damage, and reckless operation.
- The victim, 51-year-old Cambridge resident Susana Castillo, suffered fatal injuries in the crash and was pronounced dead at Massachusetts General Hospital.
- Investigators said Samura hit a car, fled that scene at high speed, drove the wrong way down Market Street, and struck Castillo’s vehicle head-on.
- Samura entered a not guilty plea at her court arraignment and remains in custody ahead of a scheduled dangerousness hearing.
Cambridge (Cambridge Tribune) October 21, 2026 – A 41-year-old Cambridge resident and licensed social worker, identified as Sosa Samura, was arrested after a multi-vehicle collision that claimed the life of a local resident.
According to official police filings and investigative disclosures, the sequence of events began shortly after 11:30 p.m. when Samura was allegedly involved in an initial traffic accident.
Rather than stopping, investigators noted that Samura fled the initial scene at a high rate of speed down several city streets, drawing the attention of another driver who attempted to follow her vehicle.
Samura’s vehicle subsequently turned down Market Street, proceeding the wrong way along the designated one-way thoroughfare toward the intersection of Columbia Street in Cambridge’s Port neighbourhood.
As reported by Mitch M. Rosenthal of Hoodline, “Samura, driving a Honda CR-V, struck Susana Castillo’s Subaru while traveling the wrong way on Market Street, pushing Castillo’s car into a tree and causing major damage to its driver’s side.”
The violent impact forced the victim’s automobile off the road and directly into a nearby tree, inflicting severe, irreversible damage to the driver’s side where Castillo was seated.
Emergency first responders quickly converged on Market and Columbia streets following emergency reports, closing down the intersection to extract the victims and process the preliminary crash site.
Castillo, aged 51, was critically injured and transported urgently to Massachusetts General Hospital, where medical staff subsequently pronounced her dead.
According to police documentation cited in local press reports, an autopsy indicated that Castillo suffered extensive fatal injuries, including tears to her aorta, internal decapitation, multiple hip fractures, and severe fractures to her leg and arm.
At the scene of the crash, investigating officers noted that Samura exhibited physical signs consistent with severe intoxication.
As reported by Boston 25 News, “When officers arrived, authorities said they observed that Samura had glassy eyes and slurred speech and detected an odor of alcohol.”
Samura was taken into custody at the scene before being brought to a nearby hospital for medical evaluation prior to booking.
What Specific Charges Does the Driver Now Face in Court?
Prosecutors from the Middlesex County District Attorney’s Office formally lodged a slate of criminal charges against Samura following her arrest.
The counts filed against her include motor vehicle homicide while operating under the influence, operating under the influence (second offense), operating under the influence causing serious bodily injury, assault and battery with a dangerous weapon, assault with a dangerous weapon, leaving the scene of property damage, reckless operation of a motor vehicle, speeding, and improper operation of a motor vehicle.
During her preliminary arraignment in Cambridge District Court, Samura entered a formal plea of not guilty to all counts brought against her.
The judicial authority presiding over the arraignment ordered Samura to remain held in custody without bail as she awaits a formal dangerousness hearing scheduled for late October.
Under state jurisprudence, a dangerousness hearing allows prosecutors to argue that a defendant poses a significant public safety threat if released on bail prior to trial.
Legal analysts note that the motor vehicle homicide charge while under the influence carries substantial mandatory sentencing guidelines if a conviction is obtained in state court.
Who Was Susana Castillo, the Victim of the Cambridge Collision?
Susana Castillo was a 51-year-old resident of Cambridge who had spent the majority of her life residing within the local municipality.
Relatives stated that on the evening of the crash, Castillo was driving home to her residence on Essex Street to assist in caring for her elderly mother, who is in her 90s.
Family members expressed shock and grief over the sudden tragic loss, noting that Castillo was widely known for her quiet dedication to her household and her family responsibilities.
Her family was notified of the disastrous collision in the early morning hours by law enforcement officials following initial identification protocols at the hospital.
Members of the local community have expressed sorrow regarding the tragedy, which occurred only blocks away from the victim’s home.
What Is the Background of This Fatal Incident and Municipal Roadway Context?
The fatal collision on Market Street highlights ongoing municipal evaluations surrounding roadway infrastructure and public safety measures across Cambridge.
Court records indicate that Samura had previous contact with law enforcement involving motor vehicle operations, including a prior OUI case dating back to 2020.
Her professional role as a local social worker was confirmed by city records and police reports filed during the booking process.
From an infrastructure perspective, the intersection of Market Street and Columbia Street sits within a densely populated residential area of the Port neighbourhood.
The City of Cambridge has actively operated under its Vision Zero municipal framework, an initiative established to eliminate traffic-related fatalities and severe injuries through street redesigns, speed enforcement, and enhanced signaling.
Despite municipal investments in traffic calming structures, complex one-way grid networks continue to present risks when drivers operate vehicles while impaired or at excessive speeds.
What Are the Future Predictions and Potential Impacts for the Local Community?
The legal proceedings surrounding Samura are anticipated to span several months as Middlesex County prosecutors gather collision reconstruction data, forensic evidence, and toxicological results.
For the immediate family of Susana Castillo, the loss presents immediate personal and caregiving challenges, specifically regarding the ongoing daily support required for her elderly mother.
For the broader Cambridge community and local residents, this tragedy is likely to intensify civic advocacy surrounding traffic safety, particularly along one-way corridors and mixed-use municipal intersections.
Local community groups and neighborhood associations are expected to press municipal authorities for accelerated infrastructure audits under Vision Zero guidelines to prevent wrong-way vehicular entries.
Additionally, the case will draw renewed public scrutiny toward repeat OUI offenses and legal oversight mechanisms for drivers previously cited for operating vehicles under the influence.
