Hayward PD Arrest Update on Homicide November 25, 2025

On July 19th, 2025, 42-year-old Hayward resident Michael Flunoy called 911 and reported that his girlfriend, 46-year-old Susana Vallejos (Lathrop resident), was suffering from a drug overdose at his residence located at 1015 Highland Blvd, and requested help. Members of the Hayward Fire Department and Hayward Police Department responded to the residence and located Vallejos unresponsive and not breathing in Flunoy's bedroom. Life-saving measures were performed; however, Vallejos was pronounced deceased at the scene. Flunoy and his roommate, David Lynn, were contacted inside the residence. Officers at the scene noted some inconsistencies in Flunoy's and Lynns' statements.

Flunoy and Vallejos were determined to be in a dating relationship for approximately two years.

The investigation was then handed over to the Hayward Police Department's Homicide Unit. Senior Homicide Detective Nick Niedenthal was assigned as the primary investigator. Flunoy and Lynn gave voluntary statements to Homicide Detectives and were released pending Susana's autopsy and other investigative steps. Senior Detective Niedenthal spent the following months methodically piecing together evidence, interviewing family members, and executing several search warrants to find additional evidence.

The results of the autopsy revealed that Susana had been murdered, and her cause of death was due to homicidal violence, which included head trauma and manual strangulation. Vallejos' toxicology report showed that she had no illegal drugs in her system at the time of her death.

The Alameda County District Attorney's Office was consulted regarding the investigation's results and autopsy findings. A judge authorized arrest warrants. On November 24th and 25th, 2025, members of the Hayward Police Department arrested Michael Flunoy and David Lynn. Flunoy was booked into jail for the aggravated murder of Susana Vallejos. Flunoy's roommate, David Lynn, was booked into jail for accessory after the fact, 32 PC.

The Hayward Police Department takes domestic violence very seriously. Anyone with knowledge of a community member suffering from domestic violence is encouraged to call the Hayward Police Department at 510-293-7000. You can remain anonymous.

Anyone with information related to this incident is asked to contact Senior Detective Niedenthal at 510-293-7176. The Hayward Police Department case number is 2025-041177.