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Investigations that have been cold for decades often accumulate an incredible amount of information. This can include thousands of pages of reports, witness interviews, lab results, photographs and investigative notes.
As detectives change assignments and evidence moves between systems, reconstructing the full story of a case can become as difficult as solving it. That was the reality in the murder of Rhonda Marie Fisher, a case that remained unsolved for 38 years.
In 1987, Fisher’s nude body was discovered down an embankment in rural Douglas County, Colorado. She had been sexually assaulted and strangled. Despite an extensive investigation at the time, no suspect was identified, and the case eventually went cold.
Nearly four decades later, the perpetrator was finally identified: Vincent Darrell Groves, a serial killer responsible for multiple homicides across the Denver metro area during the 1970s and 1980s.
Groves had died in prison in 1996.
The breakthrough in this case came through a CODIS DNA match, but confirming the case required detectives to review decades of investigative work and connect Fisher’s murder to Groves’ broader pattern of crimes.
To manage that process, analysts and detectives in the Douglas County Sheriff’s Office Cold Case Unit used Tranquility AI’s evidence analysis platform, TimePilot, to organize and review thousands of pages of case material.
Reopening the case
When the Douglas County Sheriff’s Office Cold Case Unit reopened the Fisher investigation in 2024, they were met with an overwhelming volume of reports and evidence. The case file included everything from witness interviews to crime scene photographs to suspect interviews conducted years apart.
Like many cold cases, the investigation had passed through multiple detectives over the years. While each detective added new insights, the result was a large body of information spread across different reports and time periods.
At the same time, analysts were preparing new DNA evidence for testing. Understanding how that evidence fit into decades of investigative history was critical.
Centralizing decades of evidence
Michele Kennedy, a crime analyst supervisor at Douglas County Sheriff’s Office, uploaded the Fisher case into TimePilot to centralize all the evidence.
With the case organized in one place, the team could locate and analyze information across the entire file. During evidence reviews, they used TimePilot to quickly clarify questions such as:
- What DNA testing had been conducted on specific evidence in earlier years?
- What investigative activity occurred between 1988 and 2017?
- Were there other witnesses that should have been interviewed?
- It also provided a list of all evidence items.
Having those answers immediately available helped deputies move the case forward without losing momentum. They also used the tool to generate concise case summaries that could quickly bring new detectives up to speed.
Revisiting evidence collected at the scene
The crime scene investigation done in 1987 revealed several critical pieces of evidence. The victim’s body showed clear signs of ligature strangulation. Investigative reports also noted that at least one of Rhonda’s hands appeared to have been secured with handcuffs or a similar restraining device.
Following standard protocol, paper bags were placed over Rhonda’s hands to preserve potential evidence under the fingernails and on the hands themselves.
In 2017, the Douglas County Sheriff’s Office had submitted multiple items for DNA testing, including swabs from Rhonda’s body and fingernail scrapings. The results yielded little. No usable human DNA was identified, and only a minimal amount of male DNA was detected on the left hand, insufficient for further analysis.
The case remained unresolved.
Then when the case was reopened in 2025, the team working on it decided to test something that had been overlooked for nearly four decades: the paper bags placed over Rhonda’s hands at the scene.
What seemed like a routine preservation method became the breakthrough.
DNA recovered from the bag covering her right hand resulted in a CODIS match to convicted serial killer Vincent Darrell Groves.
Connecting the pattern
After the CODIS match identified Groves as the suspect, the investigation shifted toward understanding how Fisher’s murder fit within his known pattern of crimes.
To support that effort, Kennedy created a separate TimePilot case file for Groves and uploaded records from his other homicides.
Using the platform, detectives developed victimology profiles across multiple cases, allowing them to identify patterns and better understand the scope of Groves’ activity.
This broader view provided critical context, helping confirm the connection between Fisher’s murder and the serial offender.
The outcome
After 38 years, the murder of Rhonda Fisher was officially solved.
Although Groves had died in prison years earlier, the identification closed the case and provided long-awaited answers to Fisher’s family.
For the Douglas County Sheriff’s Office, the case demonstrated how TimePilot can serve as a force multiplier for cold case investigations.
With seven cold cases solved in the past seven years, the Douglas County Sheriff’s Office remains steadfast in its mission to apply evolving technologies, revisit evidence with fresh perspectives, and forge strong forensic collaborations to ensure no victim is forgotten.
For more information, visit Tranquility AI.
