Solved via IGG NAMUS: UP8427 (SOLVED) • DOE NETWORK: 143UFNV • AGENCY CASE: WCSO-82-1184 • JURISDICTION: Washoe County Sheriff's Office, Reno, NV

Mary Silvani (Sheep's Flat Doe): Lake Tahoe Solved

The Double Breakthrough: How the DNA Doe Project simultaneously identified Lake Tahoe victim Mary Silvani and serial killer James Slice.

Archival Case File Banner: Mary Silvani (
SECTION 1: THE OFFICIAL CASE RECORD (VERIFIED FACTS)
Official Case Date July 17, 1982 (ID'd May 7, 2019)
Discovery / Last Seen Location Sheep's Flat / Mount Rose Highway, Lake Tahoe, NV
Demographic Profile Caucasian Female, 33 Years Old (5'5", 140 lbs)
Anthropological Age Estimate 33 Years Old (DOB: September 29, 1948)
Primary Investigating Agency Washoe County Sheriff's Office & DNA Doe Project
Forensic Identifiers Available Yellow Tennis Shoes with Sheepskin, Dual Victim/Suspect DNA Doe Project Solve, James Slice Perpetrator

On July 17, 1982, hikers walking near Sheep's Flat off Mount Rose Highway, overlooking the pristine alpine waters of Lake Tahoe in Washoe County, Nevada, discovered the body of a young woman lying in a dirt turnaround. She had been sexually assaulted and shot in the back of the head. For thirty-seven years, "Sheep's Flat Jane Doe" stood as one of the Sierra Nevada's most enduring mysteries.

Discovery, Clothing & Ballistics Evidence

The victim was approximately 25 to 35 years old, 5 feet 5 inches tall, and 140 pounds, with hazel eyes and short brown hair. She was dressed in a blue-and-yellow ski jacket, Levi's jeans, and distinctive yellow tennis shoes with sheepskin insoles.

Ballistics experts recovered a .22 caliber slug from her skull. Investigators noted that while her clothing labels were intact, she carried no purse or identification. A surgical laparoscopy scar on her abdomen indicated she had undergone prior gynecological medical procedures.

Chronological Case Timeline

Date / Year Location Event / Investigative Milestone
July 17, 1982 Sheep's Flat, Lake Tahoe, NV Body discovered by hikers; dubbed "Sheep's Flat Jane Doe."
2007 Washoe County Case entered into NamUs as UP8427; semen evidence from crime scene preserved.
2018 DNA Doe Project Washoe County SO detective partners with Dr. Colleen Fitzpatrick and Margaret Press.
Feb 2019 Sebastopol, CA Victim identified as 33-year-old Mary Silvani of Pontiac, Michigan.
May 7, 2019 Reno, NV Washoe County Sheriff Darin Balaam announces both victim and killer identified via genetic genealogy.
SECTION 2: PROMINENT COMMUNITY THEORIES & ANALYTICAL HYPOTHESES
Investigative Ethics & E-E-A-T Guarantee: This analytical section examines documented community theories, crowdsourced timeline comparisons from verified cold-case forums (Websleuths, Reddit r/UnresolvedMysteries, Doe Network), and geographic distribution models. In strict accordance with our nonprofit charter, no living unindicted private citizens are named or accused. All hypotheses evaluate physical markers, transportation corridors, and anatomical evidence.

The Double-Genomic Breakthrough: Victim & Killer Identified

In 2018, the DNA Doe Project sequenced bone tissue from the victim, while Washoe County detectives submitted preserved male DNA extracted from the 1982 crime scene rape kit.

In early 2019, genealogists identified the victim as 33-year-old Mary Silvani, born in Pontiac, Michigan. Mary had relocated to California in the late 1970s and had lost contact with her estranged family.

Simultaneously, genealogists ran the perpetrator's DNA profile through GEDmatch, tracing his paternal tree to Texas. Detectives confirmed the killer was James Richard Slice, a convicted serial rapist with a long history of violent assaults across California and Nevada who died in prison in 1999. Mary Silvani's case made global forensic history as the first time investigative genetic genealogy was successfully used to solve the identity of both an unidentified decedent and her unconvicted killer in a single investigation.

SECTION 3: LAW ENFORCEMENT SUBMISSION & OFFICIAL TIP LINE

Have Information Concerning This Investigation?

Even the smallest detail—a recollection of a vehicle, a seasonal acquaintance, or an old photograph—can provide the missing link to solving a multi-decade cold case. All leads submitted through official channels are cross-referenced with state databases and active forensic profiles.

Washoe County Sheriff's Office Detective Division
(775) 328-3320
Call Detective
Secret Witness Reno Tip Line
(775) 322-4900
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FBI ViCAP (Violent Criminal Apprehension)
1-800-CALL-FBI
OFFICIAL CASE CODES: NamUs: UP8427 (SOLVED) • Case Docket: WCSO-82-1184. Reference these identifiers when submitting information.
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