Harrowing new details have come out about the violent death of a young mother in front of her children.
Four-year-old Neilyann Ysam’s daughter called 911 on July 19, telling police, “My dad killed my mom.”
According to an affidavit, 28-year-old S Mate Joseph also called police, admitting he stabbed a “loved one” but said he didn’t know if she was alive.
When officers arrived at the Southeast Portland home, they found Ysam, 24, fatally stabbed. Her four children were inside, along with another child. None of the kids were hurt.
Police said the children were all under the age of six, including a baby. They were removed safely from the home.
Joseph had fled the scene but was arrested later that day in Vancouver, Washington, about 17 miles north of Portland.
Prosecutors said Ysam and her children had recently moved in with her aunt to escape alleged abuse from Joseph in their Vancouver home.
Multnomah County Deputy District Attorney Brian Davidson said the children’s experience was heartbreaking.
“It’s a horrific thing for a child to witness any act of violence — especially something this extreme,” Davidson told KATU.
Troubling history
This was not the first time Joseph had been accused of attacking Ysam.
- February 2019: Joseph was arrested for assaulting Ysam while she was pregnant. He pleaded guilty. During that incident, police shot and killed Joseph’s younger brother after he charged at them with a knife. Officers were later cleared of wrongdoing.
- March 2020: Joseph was caught with Ysam in violation of a no-contact order.
- 2025: Ysam and her children moved in with her aunt in Portland to get away from Joseph.
- July 19, 2025, 12:32 p.m.: Ysam’s daughter called 911 reporting the stabbing. Police found Ysam dead inside the home.
- July 19, 2025, 3:50 p.m.: Joseph was arrested in Vancouver and booked into jail.
- August 28, 2025: Joseph pleaded not guilty after being extradited to Multnomah County.
Joseph now faces charges of second-degree murder, first-degree burglary, and unlawful use of a weapon, police said. He also has pending DUI charges.
Shocked neighbors
Neighbors told KPTV they were stunned by the tragedy.
“It just feels like time kind of stopped,” said Annalee Dickinson. “It’s terrifying to know the children had to see that. They’ll carry it for the rest of their lives.”
Another neighbor, Teai Nguyen, said, “I just hope the family heals from this trauma, especially the kids.”
Domestic violence dangers
Experts say the weeks after leaving an abusive partner are often the most dangerous.
The Office for Victims of Crime reports that women who leave an abuser face a 75% greater risk of being killed, and 70% of domestic violence murders happen after separation.
Davidson urged survivors not to stay silent:
“To any victim of domestic violence, don’t be afraid. Law enforcement and community advocates are here to help.”
