Witness testifes that suspect in Colo. teen's slaying, dismemberment said he did it because 'she got out of line'

(CBS) DENVER - A witness testified Wednesday that the Denver man accused of killing and dismembering a 16-year-old girl said he committed the act because she "got out of line," reports CBS Denver.

Police believe Edward Romero killed Alicia Martinez, who disappeared after attending a party at his home in October 2010. Martinez's body was later found in Romero's basement. He has pleaded not guilty by reason of insanity.

Opening statements in the trial began Wednesday morning, the station reports.

According to CBS Denver, the defense claims Romero doesn't remember what happened before Martinez was killed because he blacked out, and that they believe he suffers "Dissociative Identity Disorder" due to past abuse. The defense says Romero woke up to find that Martinez was dead and decided to conceal it by dismembering her body.

Two of Romero's friends testified Wednesday, saying that Romero told them about the slaying after it happened.

CBS Denver reports that Romero's friend, Manny Gonzales, testified that Romero came into the house just after the murder and told him, "I killed Alicia. She got out of line and I had to kill her."

Romero's cousin, Francisco Aguirre, testified that Romero told him he had shot a girl at a party the night before and cut her up, the Denver Post reports.

Francesca Pagliasotti, who was Romero's girlfriend, is serving a 10-year sentence after being convicted of charges including being an accessory to murder. Prosecutors said she helped clean up the crime scene.

Another woman who prosecutors said took Martinez to the party pleaded guilty to contributing to the delinquency of a minor.