CHICOPEE, Mass. (WWLP) – The man convicted of killing 20-year-old Amanda Plasse in Chicopee in 2011 has been denied a new trial.

The state’s highest court denied an appeal by Dennis Rosa-Roman, who was convicted of first degree murder.

Plasse was killed inside her Chicopee apartment in 2011. Rosa-Roman insisted that someone else stabbed Plasse, and that he was only trying to help her.

Amanda Plasse

Rosa-Roman was arrested nearly two years later and convicted of first degree murder. He had argued for a new trial but was denied his appeal Tuesday by the Massachusetts Supreme Judicial Court. He is serving life in prison.

Rosa-Roman had been arrested in Springfield and Chicopee a number of times prior to Plasse’s murder. He had earlier been convicted of domestic assault and battery involving his fiance.