KUSA - A jury found a man accused of killing and dismembering a Denver teenager guilty of first-degree murder Monday afternoon.

Edward Romero will now face a March sentencing where he will be sentenced to serve life in prison.

After the verdict was read Romero had no reaction in court, according to 9NEWS reporter Chris Vanderveen.

Romero pleaded not guilty by reason of insanity in connection with the death of 16-year-old Alicia Martinez.

Her body was found in a home in Denver in October 2010 following a house party.

Prosecutors say Romero shot her twice and then tried to conceal the crime by dismembering her body.

"It was his plan to flush Alicia down the toilet piece by piece," Denver prosecutor Henry Cooper said.

Romero's defensedid not try to deny that he committed the crime. Instead, they argued at trial that Romero had a long history of suffering blackouts - periods of time his friends and family called "episodes."

Romero said he suffers from disassociation identity disorder, a controversial diagnosis with plenty of skeptics within the mental health community.

Testimony for the two-week trial concluded Friday.

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.