The month was September 1992, and a cold, familiar blanket of fog had settled over San Francisco’s Mission District. Inside the well-known Vuvio Cafe on Columbus Avenue, the late-night shift had ended. Three art students, Clara Reyes, 19, a photography major; Amy Sullivan, 20, a painter; and Naomi Itito, 21, an exchange student, finished cleaning and prepared to leave. They were vibrant, diligent young women, working to pay rent near Dolores Park while pursuing their artistic futures. The last blurred frames captured by the cafe’s CCTV showed the trio grabbing their coats, laughing, and turning off the lights. They locked the front door and circled toward Stevenson Alley, where the employee parking sat just behind the cafe. A neighbor high above later recalled hearing laughter and the soft tap of heels on concrete, followed by a sound like a car door closing, then an absolute, profound silence.

The discovery that followed was unnerving in its stillness. The next morning, the cafe manager found the cash register balanced and the tables neat. Yet, the employee locker room contained Clara’s coat, Amy’s transit pass, and Naomi’s canvas bag, all untouched. By early afternoon, when none of the three had arrived for classes at the San Francisco Art Institute, the first call was made to the police. Patrols were immediately dispatched. Investigators found the women’s apartment untouched, their beds made, class schedules pinned to the wall, and no sign of voluntary departure. The case was unique in its collective nature: three people vanishing simultaneously from their workplace, leaving behind all personal effects.

The search immediately focused on Stevenson Alley and the surrounding Mission District corridors. Early evidence was sparse and deeply troubling: a bloodstained scrap of artist’s canvas, later confirmed to be Clara Reyes’s blood type, was found near a storm drain, and a pair of women’s shoes, caked in mud, were recovered from the drain debris. The area also showed large, uncommon men’s shoe prints, size 10 or 11. An external encounter, likely involving violence, had occurred steps from the cafe’s back door. Later, a canvas bag, identified as belonging to one of the victims and containing art supplies and a roll of unprocessed film, was recovered from Mission Creek, where the city’s drainage system flowed. This confirmed the terrible truth: the missing persons report was now an active investigation into a profound unlawful taking of life, and the perpetrator had utilized the Mission’s intricate layout to quickly conceal evidence.

The unrecovered victims’ belongings provided a crucial lead. A taxi driver claimed he had seen the three women speaking with a tall man carrying a guitar case near Valencia Street shortly before midnight. Further investigation traced a maroon sedan near the alley, and one name quickly rose to the top of the initial suspect list: Lucas James Mercer, a 31-year-old freelance sound engineer who had worked at Vuvio Cafe, owned a matching vehicle, and matched the description of the “guitar case man.” Mercer, initially questioned, maintained his calm, reclusive demeanor and offered vague, limited responses. However, 1992’s forensic technology limited DNA analysis to RFLP (Restriction Fragment Length Polymorphism), which required large, pristine samples. The biological traces recovered—epithelial cells, blood, and hair—were degraded or insufficient. Mercer’s blood did not match the victims’ O+ blood, and the limited forensic analysis led to a devastating early conclusion: “No genetic correlation established between known samples and recovered evidence.” Mercer was technically cleared and vanished from official records, moving to a quiet rental in Glen Park, leaving the initial investigation paralyzed.

For three decades, the case file sat cold, transferred to Pier 50’s evidence locker, a heavy box sealed with red tape. Lieutenant Evelyn Cho, the young investigator who handled the case initially, refused to let it perish. She maintained a quiet, professional determination, sending yearly memos requesting the preservation of the tiny, degraded biological samples, citing that “future advancements might one day unlock doors we couldn’t open now.” She knew that time did not erase crimes, it only changed how evidence spoke.

The opportunity for justice arrived in 2024 with the launch of the Reopen 92 program, a federally funded initiative to re-examine cold cases using the revolutionary power of genealogical DNA (SNP/YSTR analysis). Evelyn Cho, now a seasoned cold case advisor, ensured the Vuvio file was prioritized. The initial focus fell on a small, overlooked artifact collected from Stevenson Alley in 1992 and never fully tested: a Camel cigarette butt. Technicians extracted DNA from the epithelial cells left on the cellulose core. The YSTR results were staggering: they revealed a male DNA profile connected with 99.9997% accuracy to the Mercer family lineage in Oregon.

The sudden, irrefutable scientific truth led investigators straight back to the man cleared in 1992. Lucas James Mercer, now 64, had lived quietly in San Francisco for decades, teaching music at a community center. The initial suspect had, through technological limitations and calculated deception, successfully eluded justice for thirty-two years. The next step was surveillance. Evelyn Cho’s team tracked Mercer to a takeout cafe in Dolores Park, where they recovered a recently discarded coffee cup and napkin. DNA extraction from the cup rim provided a contemporary sample. The resulting 23-marker STR comparison showed a perfect, 100% match with the 1992 DNA from the cigarette butt. The evidence was no longer circumstantial; it was absolute.

Armed with the final DNA confirmation, a search warrant was executed at Mercer’s Glen Park residence. The search uncovered a trove of chilling physical evidence that finally completed the narrative of the crime:

The Audio Confession: A black cassette tape labeled “Vuvio” and dated the night of the incident was found on Mercer’s desk. Forensic audio analysis revealed 14 minutes of continuous audio—Mercer’s voice singing and playing his guitar, followed by a sudden metallic clank and a short, piercing female scream, before the tape cut off. This was a sonic record of the seizure.

The Restraint Tools: A bag of nylon zip ties, still in their original Caltech Instruments packaging, was found. FTIR spectroscopy confirmed that the chemical composition and production lot matched the restraint ties found at the 1992 crime scene.

The Bloody Trophies: A beige painter’s coat, worn by Mercer, was found in his basement. Hemastics tests confirmed the presence of human blood on the coat, and DNA analysis provided an O+ match with 17 markers aligning with Clara Reyes. The coat, stained with a victim’s blood, linked Mercer directly to the violence.

The Obsession: A discarded Polaroid photograph of half Clara Reyes’s face, taken in dim light and bearing a dark smudge, revealed a disturbing fixation that went beyond a casual encounter.

On April 11, 2024, Lucas James Mercer was apprehended at a community concert where he was performing. He offered no resistance, only a weary acknowledgment: “I figured you’d come back.” Mercer was subsequently sentenced to life in confinement without parole for three counts of the unlawful taking of life. The Vuvio Cafe case, which had challenged every facet of 1990s investigation, was finally closed. The ultimate victory belonged to scientific faith, institutional perseverance, and the singular determination of Lieutenant Evelyn Cho, who insisted on preserving a few tiny cells long enough for time to catch up to the truth.