DENVER (KDVR) — There are hundreds of unsolved homicide cases, long-term missing person cases, and unidentified remains cases in Colorado where at least three years have passed since the crime happened.

The Colorado cold case task force created a list of those cases dating back to 1970. The Problem Solvers are working to highlight cold cases in our state.

Valentine’s Day murders

It has been 23 years since Stephanie Hart-Grizzell and Nick Kunselman were shot and killed at a Subway in Littleton.

The Colorado Bureau of Investigation and Jefferson County Sheriff’s Office are still working to solve this cold case.

The shooting happened at 12:47 a.m. on Feb. 14, 2000. Kunselman, 15, was working at the Subway a few blocks from Columbine High School and Hart-Grizzell, 16, was waiting for him to get off work.

An employee of the restaurant noticed the lights were on after driving by and found the bodies of Kunselman and Hart-Grizzell behind the counter.

Investigators determined that the high school sweethearts had been shot by an unknown intruder or intruders.

To this day, the case remains cold.

In 2021, the Metro Denver Crime Stoppers increased the reward in this case up to $100,000 for information leading to the arrest of the person or people involved.

 “Horrific crimes like this one have an enormous impact on our community and touch the lives of everyone. We are hopeful that the increase will result in tips that will lead investigators to the person or persons responsible for this crime and hopefully start the closure process for the family and friends of Nicholas and Stephanie, as well as the community. On behalf of our all-volunteer Board of Directors and privately and anonymously funded donors, we will continue to work with the community and our law enforcement partners until this case is solved,” Michael Mills, Board President of Metro Denver Crime Stoppers said in 2021.

If you have any information, you can contact the Metro Denver Crime Stoppers by calling 720-913-7867. You can also reach out to the Jefferson County Sheriff’s Office at 303-271-0211.

Highlighting cold cases in Colorado

Here are some of the other cases we’ve highlighted:

If you ever have a cold case you would like us to feature, please fill out this form or send an email to

The National Missing and Unidentified Persons System shows there over 20,000 open missing persons cases in the United States and over 300 in Colorado.