Brother of 2019 Vancouver Shooting Victim Charged in Portland Stabbing

A Tragic Connection Between Two Violent Incidents

A 28-year-old man currently facing charges for a fatal stabbing in a Southeast Portland home earlier this month has a deeply troubling history that connects him to another tragic event that occurred six years ago. The accused, S. Mate Joseph, is the older brother of Clayton Joseph, a 16-year-old who was shot and killed by Vancouver police in February 2019.

At the time of the shooting, S. Mate Joseph was 22 years old. According to a report from Clark County Prosecuting Attorney Anthony Golik, the incident unfolded after police responded to a disturbance involving S. Mate Joseph and his girlfriend. The report described a loud verbal and physical altercation between the two, with witnesses noting that S. Mate Joseph was intoxicated and angry.

Clayton Joseph became involved in the conflict, brandishing a knife and threatening to stab others. As the situation escalated, Vancouver Police Cpl. Roger Evans, who later retired from the department, arrived on the scene. He observed Clayton Joseph exiting an apartment complex gate and walking toward officers who were trying to subdue his brother. Evans ordered the teen to stop and show his hands, but according to his account, Clayton Joseph did not comply and instead moved toward him with the weapon raised.

Evans fired a single shot, which struck Clayton Joseph. He claimed he felt he had no other option, as he believed he would have been stabbed. When questioned about using a taser, Evans stated he did not do so because he was alone and had been trained not to use it unless another officer was present.

Golik’s report concluded that the shooting was justified. Clayton Joseph, a student at Evergreen High School in Vancouver, had recently moved to Washington from Micronesia with his family a year prior to the incident.

Now, more than six years later, S. Mate Joseph is once again at the center of a violent crime. On July 19, 2025, he was arrested in connection with a stabbing that resulted in the death of 24-year-old Neilyann Ysam near Southeast 143rd Court in Portland. According to Portland police, the victim was found dead inside a Southeast Portland residence, with five children also present in the home. Fortunately, none of the children were injured.

The circumstances surrounding the latest incident appear to echo the past. The woman identified as Neilyann Ysam in the Portland case is believed to be the same Neilyen mentioned in the 2019 Vancouver police-shooting report. Both women share the same date of birth, and officials from Vancouver police and the Clark County Prosecuting Attorney’s Office have confirmed the connection.

S. Mate Joseph is now facing multiple charges, including first-degree burglary, second-degree murder, driving under the influence of intoxicants, violating a protective order, and fourth-degree assault. He made an initial appearance in Clark County Superior Court last week and is being held without bail.

Multnomah County officials are working to bring him to Oregon to face the charges related to the recent stabbing.

As the investigation continues, the tragic events surrounding S. Mate Joseph and his family raise important questions about the impact of past incidents on current legal proceedings. The connection between the 2019 police shooting and the 2025 stabbing underscores the complex and often painful realities of violence and its long-term consequences.

For now, the community remains focused on the safety of the children who were present during the recent incident and the ongoing pursuit of justice for the victims.