Police tape and sympathy flowers still mark the perimeter of Columbine High School, but investigators hope to wrap up their work here in the next two weeks.
The heart of the investigation now is a dozen miles away in agent Chuck Davis' lab at the Colorado Bureau of Investigation. "Approximately 15 computer systems have been taken from the two suspects, the school and various associates," says Davis.
Investigators are focusing on 10 to 20 friends of Dylan Klebold and Eric Harris, serving warrants on AOL and other Internet providers, hoping to trace links between the two gunmen's computers and those who have helped plan or carry out the attack.
Lt. John Kiekbusch of the Jefferson County Sheriff's Department says, "I think there are probably some people out there who had a pretty good idea that something serious was going to happen."
One month later, 80 investigators are following 2,200 separate leads, 600 pieces of firearms evidence alone. Fragments of bombs detonated by investigators are now at several ATF labs in the region.
But it still appears to investigators that Klebold and Harris were the only two shooters, despite accounts from students about a third gunmen in a white shirt.
Sheriff's department spokesman Steve Davis says, "We found one of our dead suspects later had taken his coat off and did have a white shirt on, so there's a possibility that's who they were seeing and thought there was a third gunman."
The community here is anxious to see the crime scene become a high school once again. The school district is now telling students they should plan to return classes at Columbine High in the middle of August.