Police say cameras traced an alleged escape route, while prosecutors rely on the recordings to support murder and lying-in-wait allegations.
SAN FRANCISCO, CA — Investigators say a network of surveillance cameras and automated license-plate readers allowed them to trace an alleged attacker from an Outer Sunset killing scene to a vehicle and ultimately to the home of a retired dentist now facing seven felony charges.
Philippe Chagniot, 68, has pleaded not guilty to murder, assault with an automatic firearm, arson and three weapons-possession offenses in the May 17 death of Eric Bigone. The murder count includes a firearm allegation and a special-circumstance allegation of lying in wait. Prosecutors contend recordings captured preparations for the shooting, the attack’s immediate aftermath and the suspect’s route away from the neighborhood. The defense has denied the accusations, and the evidence has not yet been tested at a preliminary hearing or trial.
The investigative trail began in the 2500 block of 46th Avenue, where officers found Bigone, 58, suffering from multiple gunshot wounds shortly after 5 a.m. Police and paramedics tried to save him, but he died at the scene. Authorities did not immediately identify a suspect. Ten days later, homicide investigators arrested Chagniot and said they had developed probable cause through surveillance review, movement analysis and other evidence collected during the inquiry.
Prosecutors allege that at about 5:09 a.m., a masked person dressed in dark clothing rode a bicycle toward Bigone’s residence. The person allegedly applied spray paint to several surveillance cameras in an attempt to block their lenses. That conduct is not listed as a separate count in the public charging announcement, but it forms a significant part of the prosecution’s theory that the killing was planned and that the attacker tried to conceal his identity and actions.
The camera interference was only partly successful, according to investigators. Other recordings allegedly showed the cyclist moving through nearby streets. Police said they used those images, along with Flock cameras that capture license plates and vehicle information, to connect the bicycle route to a car. They then traced the car toward Chagniot’s residence and examined its movements before and after the shooting. Prosecutors say the combined records show a path from Chagniot’s home to Bigone’s neighborhood and back.
That reconstruction matters to the murder case because the publicly described recordings do not appear to depend on one uninterrupted video. Investigators instead assembled multiple observations from separate locations. At trial, prosecutors would likely need to establish when each recording was created, whether its clock was accurate, who maintained it and how detectives concluded that the same cyclist, bicycle or vehicle appeared across the sequence. The defense would have an opportunity to challenge gaps, image quality and the identification methods used.
Near Bigone’s home, the masked person allegedly set burning material on top of a parked car and then hid nearby. Bigone came outside with a shovel and tried to remove the material, prosecutors said. The person prosecutors identify as Chagniot allegedly approached from behind carrying a fully automatic MAC-10 equipped with a silencer, shot Bigone in the back and fired additional rounds after he fell. Authorities say the cyclist then left the area in a manner captured by surveillance equipment.
The claimed recordings perform several jobs in the criminal case. They are offered as evidence of identity and location, but prosecutors also use the sequence to support intent and premeditation. The alleged mask, dark clothing and efforts to cover cameras may be presented as signs of concealment. The fire may be offered as evidence that Bigone was deliberately drawn outside. The period of hiding and the approach from behind are central to the accusation that Chagniot killed while lying in wait.
Prosecutors charged arson under a separate count based on the vehicle fire. They also charged assault with an automatic firearm, possession of an automatic firearm, possession of a silencer and possession of a high-capacity magazine. The murder charge alleges Chagniot personally discharged a firearm and caused Bigone’s death. Together, the counts show that the District Attorney’s Office intends to prosecute the alleged preparation, weapon possession and attack as distinct criminal acts rather than treating them only as facts within a single homicide count.
After following the digital trail, police arrested Chagniot without incident May 27. Investigators then searched his residence and reported seizing evidence connected to the case. Court coverage said officers found a machine gun, silencer and high-capacity magazine. Public statements have not disclosed complete forensic results, including whether ballistics testing matched a recovered firearm to bullets or cartridge cases from the scene. The existence of seized equipment may support possession counts, but any link to the killing must be established through evidence that can be admitted in court.
Digital-location evidence also has limits. A license-plate reader can document that a vehicle associated with a particular plate passed a camera, but it does not always show who was driving. A residential camera may capture clothing or movement without clearly showing a face. Prosecutors can attempt to close those gaps with ownership records, search results, communications, forensic testing or witness testimony. Defense attorneys can argue that the evidence shows a vehicle or object rather than proving who committed a crime.
Chagniot’s attorney entered not guilty pleas to all charges at the May 29 arraignment. The defense did not request immediate bail, and Chagniot has remained jailed while prosecutors seek detention without bail. The court appearance settled no factual disputes. It formally advised Chagniot of the accusations and placed his denial on the record. His lawyer may later file motions challenging the legality of searches, the use of particular records or the admissibility of statements and physical evidence.
A preliminary hearing is expected to provide the first extended public examination of the prosecution’s proof. Prosecutors may call investigators to explain how they collected the recordings, linked the bicycle to the vehicle and identified Chagniot. The defense will be allowed to question those witnesses. The judge’s task will be to decide whether probable cause supports the charges, not whether the prosecution has proved guilt beyond a reasonable doubt. A finding for the prosecution would keep the case moving toward trial.
The automatic-firearm and accessory charges may require technical evidence apart from the digital trail. Prosecutors must establish that the weapon met the legal definition of an automatic firearm, that the device was a prohibited silencer and that the magazine fell within the charged category. They must also prove knowing possession by Chagniot. Firearms examiners, photographs, test results and records documenting where items were recovered could therefore become important even if those items are not conclusively tied to the fatal shots.
Authorities have described Chagniot as Bigone’s landlord but have not publicly identified a motive in the criminal case. The prosecution does not need a publicly announced motive to file charges, and the camera evidence is being presented primarily as a record of conduct and movement. Still, motive evidence may emerge through documents, electronic communications or witness testimony as investigators continue reviewing the relationship between the two men.
No jury has reviewed the recordings, no judge has ruled that the seized items are admissible, and no trial date has been set. For now, the digital trail remains the prosecution’s publicly described bridge between a masked cyclist seen near Bigone’s home and the former dentist accused of carrying out the killing. Chagniot is expected back in court in late August as attorneys prepare for the preliminary-hearing stage.
Author note: Last updated July 18, 2026.