Stabbing on Mendocino Avenue: Suspect Robert Dean Arrested After Unprovoked Attack in Santa Rosa

Santa Rosa, CA — Late Monday night, a violent and unprovoked stabbing incident on the 2300 block of Mendocino Avenue in Santa Rosa left one individual seriously injured and led to the arrest of the alleged attacker, 37-year-old Robert Dean, a resident of New Mexico.

At approximately 11:48 p.m. on June 23, 2025, the Santa Rosa Police Department Communications Center received a 9-1-1 call reporting an assault. The caller stated that a person had been stabbed and that multiple bystanders were restraining the suspect at the scene.

Officers, Bystanders Act Swiftly

Santa Rosa Police officers, assisted by Santa Rosa Junior College Police, responded immediately. Upon arriving, they detained Robert Dean and administered emergency first aid to the victim. Personnel from Sonoma County Fire and Santa Rosa Fire also responded and transported the victim to Memorial Hospital with serious injuries. Due to the sensitive nature of the case, the victim’s identity has not been released.

According to multiple witness accounts, Dean allegedly attacked the victim from behind with a pocketknife, completely without provocation. Witnesses acted quickly and bravely, physically restraining Dean and successfully disarming him until law enforcement arrived.

While the Santa Rosa Police Department has commended these individuals for their quick action, officials have also reminded the public that intervening in violent incidents can be extremely dangerous.

“The actions of these bystanders were courageous and may have prevented further injury,” said an SRPD spokesperson. “However, we strongly urge individuals to call 9-1-1 and avoid physical intervention unless absolutely necessary.”

Suspect in Custody, Facing Attempted Murder Charge

Robert Dean was arrested on the scene and has been booked into the Sonoma County Correctional Facility on a charge of Attempted Murder under California Penal Code 664/187. At this time, investigators have not found any evidence of a prior relationship between Dean and the victim, and the motive for the attack remains unclear.

Authorities are continuing their investigation and are asking anyone who may have witnessed the incident or who has additional information to come forward.

“Our detectives are thoroughly reviewing all witness statements and nearby surveillance footage,” said the SRPD. “We are committed to ensuring justice for the victim and accountability for the suspect.”

Commitment to Public Safety

The Santa Rosa Police Department emphasized its continued dedication to the safety of the community and praised the collaboration with partner agencies and community members that helped bring the incident under control so quickly.

Anyone with further information is urged to contact the SRPD Violent Crimes Investigations Team at (707) 543-3590 or submit an anonymous tip through the department’s website at www.santarosapd.com.

Summary:

• Incident: Stabbing on Mendocino Avenue, June 23 at 11:48 p.m.
• Suspect: Robert Dean, 37, of New Mexico
• Victim: Sustained serious injuries, transported to Memorial Hospital
• Charge: Attempted Murder (PC 664/187)
• Investigation: Ongoing; public encouraged to share information