SAN JOSE, Calif. (KRON) — Police said a San Jose man intentionally poisoned his mother with fentanyl and caused her death. Bradley Dexter, 40, was booked into a Santa Clara County jail this week on suspicion of homicide, poisoning, and elder abuse.

Dexter’s mother was found dead inside a home on June 6. A sheriff’s coroner later classified the woman’s death as a homicide, and her cause of death was determined to be an “intentional fentanyl poisoning,” San Jose Police Department Officer Steve Aponte wrote.

“SJPD Homicide Detectives then began a comprehensive and thorough investigation into this incident and identified Bradley Dexter, a resident of San Jose and adult son of the victim, as the potential suspect,” Aponte wrote.

Earlier this month, police discovered that Dexter was also responsible for a violent attack against his father. The father suffered serious injuries. Police did not say when or where the father was assaulted.

Patrol officers arrested Dexter on Sept. 25. The motive and circumstances surrounding the deadly poisoning are still under investigation, police said.

Anyone with information is asked to contact Det. Sgt. Barragan #4106 or Det. Van Brande #4542 of the SJPD’s Homicide Unit by calling (408) 277-5283.

There have been 28 homicides in San Jose this year.