Key Points
- Sosa Samura, 41, of Cambridge, faces multiple charges, including motor vehicle homicide while operating under the influence (OUI), following a crash.
- The collision killed 51-year-old Cambridge resident Susana Castillo (also listed as Casillo in court records), who died at Massachusetts General Hospital.
- Investigators said Samura fled an earlier minor collision and drove at high speed the wrong way down Market Street in the city’s Port neighborhood.
- Authorities charged Samura with motor vehicle homicide while OUI, OUI second offense, OUI causing serious bodily injury, assault and battery with a dangerous weapon, leaving the scene of property damage, and reckless operation.
- Samura pleaded not guilty at her arraignment and remains in custody ahead of a dangerousness hearing.
Cambridge (Cambridge Tribune) October 22, 2026 — The Middlesex District Attorney’s Office and the Cambridge Police Department confirmed that Sosa Samura, a social worker residing in Cambridge, was taken into custody following the incident at the intersection of Market and Columbia streets in the city’s Port neighborhood.
Emergency response crews were dispatched to the scene shortly after 11:30 p.m., where they found a multi-vehicle wreck with significant structural damage to the impact vehicles.
The victim of the fatal impact was identified as 51-year-old Susana Castillo, a lifelong Cambridge resident who was traveling home to care for her elderly mother. First responders rendered immediate assistance and transported Castillo to Massachusetts General Hospital, where emergency medical personnel subsequently pronounced her dead.
How Did The Fatal Cambridge Incident Unfold?
According to preliminary investigative accounts detailing the sequence of events leading up to the crash, the emergency began several streets away. Authorities indicate that Samura was involved in an earlier property damage collision and allegedly fled the scene without stopping.
The driver of the initial struck vehicle followed Samura’s Honda CR-V as it travelled at an elevated rate of speed through residential roadways. Samura then turned down Market Street, proceeding the wrong way against the designated one-way traffic movement.
Upon entering the intersection with Columbia Street, Samura’s vehicle collided directly with the Subaru driven by Castillo. The momentum of the impact drove Castillo’s vehicle off the main path and into a nearby tree, resulting in devastating severe damage concentrated on the driver’s side.
As reported by Mitch M. Rosenthal of Hoodline, emergency documents cited from local authorities confirmed that “Samura sped away from another crash” prior to entering the one-way section of Market Street.
What Evidence And Formal Charges Have Law Enforcement Presented?
Officers arriving at the crash site reported observing distinct signs of impairment during their interaction with Samura. Police reports note that she exhibited glassy eyes, slurred speech, and an odor of alcohol.
Following her arrest at the scene and subsequent medical evaluation at an area facility, law enforcement officials filed a comprehensive list of criminal complaints.
The formal charges include motor vehicle homicide while operating under the influence, operating under the influence as a 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.
As reported by Natalie Khait of Boston 25 News, official court filings specify that “at her arraignment on Tuesday, Samura was ordered held pending a dangerousness hearing scheduled for Oct. 27”.
During the initial court appearances, Samura entered a plea of not guilty to all counts. She remains detained in custody as prosecutors prepare for the upcoming hearing to determine whether she presents an ongoing risk to public safety.
What Is The Background Of This Particular Development?
This tragic fatal collision highlights ongoing concerns regarding repeat traffic offenses, localized street design, and public safety enforcement. Records brought forward during the preliminary proceedings indicated that Samura had a previous operating under the influence case dating back to 2020, leading to the current offense being elevated to a second OUI charge.
The tragedy also reopens civic discussions around road safety and traffic infrastructure in the municipality. The intersection of Market and Columbia streets sits within the Port neighborhood, an urban area characterized by narrow one-way side streets and tight grid intersections.
Municipal authorities in Cambridge have actively operated under the Vision Zero policy framework, aiming to eliminate serious traffic-related fatalities and injuries across the city.
Traffic datasets and accident tracking are routinely monitored by city urban planners to identify hazardous roadway configurations, evaluate speed limits, and reassess one-way signage visibility across residential neighborhoods.
What Are The Future Predictions For Local Residents And Area Drivers?
This development will likely spur several legal, policy, and community shifts over the coming months:
- Stricter Judicial Scrutiny for Repeat Offenses: The upcoming dangerousness hearing and criminal trial are expected to intensify calls for strict legal measures regarding repeat impaired driving offenses, potentially influencing how bail and detention decisions are handled in similar cases.
- Accelerated Roadway Safety Audits: Local residents in the Port neighborhood and surrounding Cambridge districts will likely demand immediate physical traffic-calming interventions, such as enhanced wrong-way signage, raised crosswalks, and additional signalization at key urban intersections.
- Increased Municipal Focus on Vision Zero Initiatives: Municipal leaders will face renewed community pressure to review citywide collision data and re-evaluate high-risk street corridors to prevent future vehicle fatalities.
