Am I the Killer?

Peter, a brain-injured veteran with a motive, is arrested for murder. The victim bullied Peter throughout his youth, and, on the night of the murder, he discovered the bully stole his fianceé while Peter served overseas.
Detective Luca leads the investigation but believes the marine's inability to recall events on the fateful night are injury related and not an attempt by Peter to hide the truth.
As political pressure to solve the case rises, Luca pursues other leads but evidence points at Peter. Even his brother, Vinny, who dropped everything to help his injured brother recover, begins to question Peter’s guilt.
Peter's lawyers, faced with a client either unwilling or unable to assist in his own defense, recommend he cop a plea. Frustrated, Luca attempts to move on but is haunted by an old case that fuels his obsession to determine the truth about what happened that night.