In October 2002, 17-year-old Jenna Nannetti was murdered in Holt, California, by her 20-year-old husband, Michael Joseph 'Mike' Simons, along with his teenage lover, Katherine 'Katie' Belflower, and their friend, Jeff Hamilton. Mike and Jenna had married in June 2002, but four months later Mike moved out to live with Katie. Believing falsely that Jenna had a $100,000 life insurance policy, Mike and Katie plotted to murder her to buy a house, recruiting Jeff Hamilton by offering him a place to live in exchange for using his Dodge Neon. On October 6, 2002, Mike lured Jenna to Katie's home under the pretense of marriage reconciliation, where Katie struck Jenna in the head with a baseball bat. When Jenna survived, Mike convinced her to travel with him to Whiskey Slough in Holt, where Katie and Jeff were waiting. Mike retrieved a shotgun from Jeff's car, shot Jenna multiple times, reloaded, and killed her. The trio then burned Jenna's Ford Mustang at Mountainous Bar in Alameda County. The case remained unsolved until March 1, 2003, when police caught Katie and Jeff attempting to strangle another young woman, Aspen Lum, whom Katie viewed as a romantic rival. Following their arrest, Jeff and Katie confessed to both crimes. In 2005, Jeff Hamilton pleaded guilty to second-degree murder, Katie Belflower pleaded guilty to murder, and Mike Simons was convicted of murder and sentenced to life without parole.
Country: United States
State/Province: California, United States
City/Region: Holt
Incident Type: Murder
Relationship Status: Separated
Relationship Duration: Approximately 4 months (marriage before separation)
Incident Date: Oct. 6, 2002
Relationship Origins:
Relationship Stages:
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Motives:
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How the relationship or connection began.
Approximately 4 months (marriage before separation)
Important relationship phases recorded for this case.
Reported red flags or early concern points.
Contributing factors and possible motives from the available sources.
2002-10-06
Recorded relationship or case outcome.
English labels are shown first. Original-language titles are preserved for source verification.
Dr. Grande · Original language: English
Immature 'Scooby-Doo Villain-Style' Criminals Murder Romantic Rival | Jenna Nannetti Case Analysis
Infidelity
The relationship was characterized by rapid escalation, early marital breakdown, and extreme financial motive. Four months after marrying Jenna Nannetti, Michael Simons abandoned her to live with Katherine Belflower. Driven by a false belief that Jenna held a $100,000 life insurance payout, Simons and Belflower conspired to eliminate Jenna to fund their shared housing goals, utilizing false reconciliation promises as a trap.
Initial investigation faced significant cold-case risk due to lack of direct physical evidence connecting Simons to the crime scene at Whiskey Slough. The break occurred six months later on March 1, 2003, when Park Police intercepted Katie Belflower and Jeff Hamilton attempting to strangle Aspen Lum. Jeff Hamilton's subsequent confession exposed the full details of Jenna Nannetti's murder, leading to convictions for all three co-conspirators in 2005.
Initial confusion arose from the burnt vehicle left miles away from the murder scene at Mountainous Bar in Alameda County, while Jenna's body was not recovered until 12 days later in Holt, California. Investigators lacked direct evidence tying husband Mike Simons to the scene until co-conspirator Jeff Hamilton provided a detailed confession after a separate crime.
Mike Simons lured Jenna Nannetti under the guise of saving their marriage on October 6, 2002. Outside Katie's house, Katie struck Jenna with a baseball bat. When Jenna survived and attempted to seek family help, Mike manipulated her into driving to Whiskey Slough under the premise of confronting Katie. At the location, Mike retrieved a shotgun supplied by Katie and Jeff, fatally shot Jenna, dragged her body into the grass, and subsequently torched her car at a distant parking lot using a road flare.
High-risk indicators included severe deception, sudden abandonment following short-duration marriage, persistent vulnerability and isolation of the victim, and reckless group-facilitated violence. The perpetrators demonstrated callous disregard for human life and severe moral disengagement, repeating homicidal behavior months later against a second target.
False financial assumptions (unverified insurance policies) can act as catastrophic triggers in high-conflict, low-maturity dynamic relationships. Serial conspiratorial violence can quickly recur if initial crimes remain undetected due to perpetrator perception of impunity.
Mike Simons moving out four months into the marriage to live with Katie Belflower, coupled with persistent deceptive attempts to arrange isolated meetings with Jenna despite ongoing conflict.
The discovery of Jenna's torched Mustang on October 7, 2002, her voicemail messages detailing a baseball bat attack, and the traffic stop on Mendenhall Road six months later involving latex gloves and rope.
Detailed confessions by Jeff Hamilton and Katie Belflower, matching shotgun wound ballistics, recovery of the victim's body in Holt, and phone record/voicemail evidence.
Jenna's grandmother Linda Nannetti stated Jenna left in her Mustang on October 6 to meet Mike. Voicemail left by Jenna to her father stated: 'Call me now I probably got a concussion I just got hit upside the head with a baseball bat... I need your help call me.'
The investigation transitioned from a stalled missing-person/homicide inquiry into solved convictions after an unrelated attempted murder arrest on March 1, 2003, produced confessions implicating all three conspirators.
No significant investigative facts remain unresolved following full confessions and criminal trial convictions of all three participants in 2005.