By Keith Coffman
DENVER (Reuters) - A U.S. Army officer who initially blamed his identical twin brother for a series of sexual assaults on underage girls because they share the same DNA pleaded guilty to the crimes on Tuesday, prosecutors said.
First Lieutenant Aaron Gregory Lucas, an artillery officer stationed at Fort Carson, Colorado, pleaded guilty to kidnapping, sexual assault on a child, indecent exposure and other charges, said Lee Richards, spokeswoman for the El Paso County district attorney's office.
Lucas, 32, was linked by DNA to the crimes in Colorado, as well as to other assaults in Texas and Alabama where he was previously stationed, prosecutors said.
He initially pleaded not guilty to charges that between 2009 and his arrest last year that he either enticed or exposed himself to nearly a dozen girls in the Colorado Springs area, and sexually assaulted an 8-year-old girl.
A district court judge ruled that Lucas's lawyers could pursue the mistaken identity defense, which Richards said was not backed up by the evidence.
"There was no information uncovered by investigators to suggest his brother had anything to do with this, or that he was even in the same states where the assaults occurred," she said.
Under a plea agreement reached with prosecutors and approved by the judge, Lucas will serve 20 years to life for the assaults, Richards said.
Lucas's lawyer, Theodore McClintock, could not immediately be reached for comment, but the Colorado Springs Gazette newspaper quoted him after the hearing as saying the mistaken identity claim was a "legal, tactical decision."
"He loves his family. He doesn't want to create problems for them," McClintock said, according to the Gazette.
Longtime Colorado criminal lawyer and legal analyst Wil Smith said judges typically allow the defense wide latitude in exploring other possible explanations for incriminating evidence.
"But it's very difficult to argue there were issues with the DNA testing, or there's an alternate suspect when you can't put the other person at the scene of the crime," Smith said.
Lucas is set to be sentenced in February.
(Editing by Dan Whitcomb and Leslie Adler)