Police announced earlier that they had located a van that was seen in the area, but later determined the van was not the vehicle that hit the victim.
At 9:48 p.m., Longmont Police responded to a fight on the 2200 block of Main Street. Police could not locate all the fighting parties involved, so they left the scene.
A few minutes later, officers returned to the scene when they heard about another fight in the same area.
Police say as one of the fighters ran away from the encounter, he was hit by a vehicle traveling southbound on Main Street. The victim who died was 16 years old.
Tuesday, friends who knew the teen showed up with flowers. They were clearly heartbroken over the loss of their friend.
"My heart dropped. He was like my little brother. It's hard." Haley Landreth said.
Anyone with information on this crime, or any other crime, is asked to call the Longmont Police Department at 303-651-8501 or Northern Colorado Crime Stoppers at 1-800-222-TIPS (8477).