PARK COUNTY, Colo. -- Investigators determined 17-year-old girl was "purposefully set on fire and burned alive" inside her home in Colorado, according to KDVR.
Park County Sheriff Tom McGraw said Monday they have yet to arrest three people who spent a "significant amount of time inside the home" with Maggie Long during her death on December 1, 2017 in Bailey, Colorado.
Long was reported missing after she did not show up to a concert at Platte Canyon High School. Her remains were found at her burned home off Park County County Road 43 in Bailey.
Authorities released new sketches of the suspects but said the suspects may have changed appearances since the incident. McGraw said more sketches may be forthcoming.
The sheriff said the suspects likely targeted Long's home, but didn't necessarily have prior intention to target her.
"We believe this was a targeted crime and that there are at least three suspects still at large," McGraw said. “Maggie was purposely set on fire and burned alive."
Dozens of DNA samples have been collected. McGraw said one of the suspects may have suffered an injury from that night.
McGraw said the reward was increased to $50,000 and a new website was created for the public to give anonymous tips.
More than 100 people were ruled out based on hundreds of tips from the public.
"Somebody knows what happened," said McGraw. "Every tip will be addressed."
The Colorado Bureau of Investigation, ATF and the FBI Denver Division will continue to assist the Park County Sheriff's Office with the investigation.