The Colorado Bureau of Investigations is using an innovative technique to solve cold cases by distributing playing cards with photos of homicide victims.
According to the AP, police are hoping the public will provide details on each card to further along unsolved cases.
There are currently 1,600 unsolved cases, including 1,330 homicides, in Colorado, the AP noted.
The deck of cards, which was first distributed in October, feature two victims who were found south of Breckenridge in 1982. The Colorado Bureau of Investigations sent a second round of playing cards to local law enforcement agencies and detention centres in January.
According to the AP, the state initially ordered 5,000 card decks, but hope to distribute an additional 10,000 in the next year. Each deck is priced at $1.14 (£0.76).
Audrey Simkins, the agency's cold case analyst, told the AP, "We have gotten about four dozen calls that have come in and are opening the doors on those circumstances. Not all of them are going to pan out. But at least the phone's ringing."
The cards are produced by Effective Playing Cards & Publications, ABC 7 reported. The company has provided the cards to state agencies, law enforcement and crime stopper units throughout the country for the last two years.
"We have more than 30 individual decks in use at this time, including the first ever statewide deck for Florida which is currently being distributed to every prisoner in the State. New York, Texas, Missouri, Ohio, Iowa, California and Washington along with agencies in Canada are all working toward implementing our cards into their area," the company's website states.
ABC 7 reported that CBI has two more decks, with 52 unsolved cases each, in the works.