SAN JOSE, Calif. (KRON) — A San Jose man said he poisoned his mother’s cups of oat milk and wine with fentanyl, according to recently filed court documents. Investigators allege that Bradley Dexter, 40, confessed during a police interrogation to intentionally poisoning his mother with the powerful opioid, and nearly killing his father with a metal baton.

Kathleen Dexter’s death was classified as a homicide and her son is charged with murder. Court documents noted a possible motive behind why the son allegedly wanted to kill his 73-year-old mother.

During their investigation into the woman’s sudden death, San Jose Police Department officers interviewed her family members and friends. “Several informed us that Kathleen and the suspect did not have a good relationship,” SJPD Det. Catherine Van Brande wrote in court documents.

“Kathleen’s best friend … told us that Kathleen had recently told her that the suspect had threatened to kill Kathleen,” Brande wrote. The victim told her best friend that if anything terrible happened to her, the son was likely behind it.

The best friend told detectives that the victim and her son were embroiled in an ongoing dispute over inheritance property and stolen social security benefits.

Bradley Dexter’s son found Kathleen Dexter dead inside her bedroom on Utopia Place in San Jose on June 6, 2023, court records show. The boy called 911 and told dispatchers that his grandmother was not breathing and not conscious. Paramedics pronounced the grandmother deceased at the scene. The boy, his father, and grandparents all lived in the same house, court records show.

The boy told police that he last saw his grandmother alive the previous night. He also told police that his grandmother had been sick and vomiting for the last few days with an unknown illness.

On July 18, a Santa Clara County Sheriff’s coroner alerted SJPD’s Homicide Unit that he classified Kathleen Dexter’s death as a homicide, and a toxicology report found high levels of fentanyl in her blood. “Dr. Koolaee had access to the victims’ medical records, and confirmed she was not prescribed fentanyl,” Det. Brande wrote.

Homicide detectives’ suspicions of Bradley Dexter were heightened after he allegedly beat his 76-year-old father with a metal baton on Sept. 20. The father told police that his son struck him 12 times and he suffered major injuries.

Bradley Dexter was hauled into the San Jose police station for an interrogation on Sept. 25. He allegedly confessed to police that he attacked his father, and killed his mother by poisoning her wine and oat milk with fentanyl. Det. Brande wrote, “The suspected admitted to assaulting his father with a metal baton. He stated that he was prepared to kill his dad but decided to show him mercy. The suspect also admitted (to) killing his mother.”

Court documents state that Bradley Dexter put fentanyl into his mother’s oak milk on the day of his son’s graduation, about two weeks before she died. After she recovered in a hospital, he poisoned her again by placing fentanyl in her wine, Det. Brande wrote.

SJPD officers arrested Bradley Dexter after the interrogation. The defendant remains in a San Jose jail with no bail. His next court appearance is scheduled on November 13 for arraignment.