The reward was raised in the previously offered $12,000, neighborhood affiliate FOX 31 reported.
"The benefit in this instance is currently around $100,000. This demonstrates is people still attention, people need answers, folks need justice for Nick and Stephanie along with the whole community," Metro Denver Crime Stoppers' Sarah Johnston informed the news channel.
As per a post on the Crime Stoppers Facebook webpage, a Subway worker called police only after 12:45 a.m. on Feb. 14, 2000, after passing the restaurant on West Coal Mine Avenue and discovering the shop's interior lights were left .
Officials stated Kunselman was functioning in the shop, while Hart-Grizzell was waiting for him to complete his shift, when a couple of burglary entered and, sooner or later, started fire.
"With this considerably increased benefit, those who have not come forward with their advice will be more prone to do so today," said Jefferson County Sheriff Jeff Shrader. "We're now continuing our diligent work to deliver justice to Nicholas and Stephanie."
Anyone who thinks they have information in relation to the situation can telephone 720-913-7867 or submit an application online by clicking here.