Police think there may be as many as 20 victims, all of them under 12 years old.
Fountain police Sgt. Scott Gilbertsen identified the suspect as 31-year-old First Lt. Aaron Gregory Lucas, an infantry officer stationed at Fort Carson.
Gilbertsen says Lucas was targeting girls as far back as 2010 when he arrived in Colorado and Fort Carson.
The crimes Lucas is accused of range from exposing himself, to kidnapping and sexual assault.
Gilbertsen calls Lucas "a predator," who patrolled the streets searching for victims.
Gilbertsen first began investigating several incidents in July.
"The suspect description and the suspect vehicle description was the same," Gilbertsen said.
A man was targeting preteen girls, exposing himself, and trying to lure them into his car.
Gilbertsen said while he was investigating the sexual assault cases, more incidents started to happen.
Soon, there were 10 victims in Fountain alone.
Police say Lucas also preyed on young girls in Colorado Springs and around El Paso county. He said some incidents happened up to two years ago.
"It just really quickly became apparent that this was the same person, the same man," Gilbertsen said.
The big break in the case came in September, when a Fountain school resource officer spotted a man who looked suspicious.
"It's a one in a million shot that he saw him. He did and he brought me that information," Gilbertsen said. "And that's when the real light bulb went on."
Gilbertsen reached out to the military, district attorney, and two other police agencies.
They formed a task force, shared information, and were able to connect all the cases to Lucas, who faces a growing list of charges. Additional counts were filed Saturday night.
Gilbertsen said he is gratified that Lucas is off the street. He said there could be up to 20 victims.
Lucas is in the El Paso county jail on more than $2 million dollars bond.
(KUSA-TV © 2012 Multimedia Holdings Corporation)