On January 23, 2017, celebrity hairstylist and beauty executive Fabio Sementilli was found stabbed to death in the backyard of his Woodland Hills, California home by his 16-year-old daughter. Investigators uncovered an extramarital affair between Fabio's wife, Monica Sementilli, and her racquetball instructor, Robert Lewis Baker. Forensic evidence and digital records linked Baker and an accomplice, Christopher Austin, to the physical attack, while surveillance logs, encrypted messages, and financial motives pointed to a conspiracy with Monica. Baker pleaded no contest in 2023, Austin pleaded no contest in early 2025, and Monica Sementilli was convicted of murder and conspiracy to commit murder in April 2025.
Country: United States
State/Province: California, United States
City/Region: Woodland Hills
Incident Type: Domestic Violence Homicide
Relationship Status: Married
Relationship Duration: Approximately 20 years
Incident Date: Jan. 23, 2017
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How the relationship or connection began.
Approximately 20 years
Important relationship phases recorded for this case.
Reported red flags or early concern points.
Contributing factors and possible motives from the available sources.
2017-01-23
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Dr. Grande · Original language: English
Did Cheating Wife Conspire to Murder Celebrity Hairstylist? | Monica Sementilli Case Analysis
Infidelity
The relationship pattern involved a long-term marriage alongside a secret, highly intense extramarital affair between Monica Sementilli and her racquetball instructor, Robert Lewis Baker. Communication records revealed thousands of phone calls and extensive encrypted messaging leading up to the homicide. The fatal dynamic escalated from illicit romantic attachment and financial greed into a deliberate conspiracy to murder the victim for personal freedom and a $1.6 million life insurance payout.
Police initially considered neighborhood burglars due to a missing security DVR and stolen vehicle, but shifted focus to Monica and Baker upon discovering their affair. DNA testing matched blood at the scene to Baker, who had cut his finger during the assault. Surveillance footage tracked Monica's coordinated movement at a nearby Target store and remote digital access to her home security IP address. Both Monica and Baker were arrested on June 14, 2017. Baker pleaded no contest in 2023 to life without parole. Baker's social media led police to identify Christopher Austin in October 2024, who pleaded no contest to second-degree murder in early 2025. On April 11, 2025, Monica Sementilli was convicted of murder and conspiracy.
Initial confusion arose because the victim's house appeared targeted by local burglars, and the security system DVR had been removed. Additionally, investigators initially knew Baker was present at the crime scene via DNA, but could not immediately identify the second jogging figure seen on neighborhood camera footage until 2024. Baker also publicly claimed full responsibility and insisted Monica was uninvolved, creating conflicting defense narratives regarding whether Baker acted independently.
On the afternoon of January 23, 2017, Monica established an alibi by driving to a Target parking lot, briefly meeting an individual suspected to be Baker, and prompting her daughter Jessica to leave the house. While Monica accessed the home security feed remotely, Baker and Austin jogged to the residence, stabbed Fabio seven times, detached the security DVR, and fled in Fabio's Porsche. Isabella Sementilli returned home shortly after and discovered her father's body. Subsequent analysis of thousands of phone logs, encrypted chats, shared surveillance passwords, and recorded police vehicle conversations reconstructed the conspiracy.
The case illustrates a severe threat pathway where extramarital intimacy converged with extreme financial incentives and pre-incident surveillance sharing. Monica provided security access details to Baker months prior to the crime and monitored the home remotely during the attack. The presence of high-frequency secret communication and emotional detachment following a spouse's sudden death served as critical indicators of conspiratorial violence.
Key indicators included intense communication volume (26,000 phone calls between lovers in a single year), sharing digital home security credentials, complete absence of grief following a horrific spousal homicide, and persistent financial pursuit of life insurance proceeds while under active murder investigation.
Early signals included high-frequency secret communication between Monica and Baker, exchange of home security system login credentials six months prior to the crime, and Monica's remote monitoring of the home security system during the attack.
Key clues included blood found at the crime scene matching Baker, neighborhood video surveillance showing two disguised joggers near the residence, Monica's precise arrival time shortly after the discovery, and social media posts that eventually led to accomplice Christopher Austin.
Strongest evidence included DNA matching Baker at the scene, digital records showing remote IP access from Monica's phone during the murder, 275 encrypted messages exchanged around the date of the crime, and recorded conversations inside a police vehicle following arrest.
Isabella Sementilli reported finding her father slumped in a chair in the backyard and called 911 at 4:54 p.m. Christopher Austin testified that he assisted Baker in the assault but had no direct contact with Monica, receiving all directives through Baker.
Follow-up investigations overturned the initial burglary theory by exposing the affair and matching scene blood to Baker. In 2023, Baker pleaded no contest and took sole blame, but ongoing digital analysis of Baker's social media in late 2024 exposed Austin as the second perpetrator, culminating in Monica's conviction in April 2025.
It remained unconfirmed whether Monica's remote cell phone connection to her home IP address during the crime was strictly used for live video monitoring or streaming data, though prosecutors maintained it was part of her active role in the conspiracy.