A 26-year-old Brooklyn man has been convicted of assault as a hate crime in the October 2014 attack on a transgender woman that left her traumatic brain damage.

Prosecutors said Friday Marshawn Sonds, of Brownsville, faces up to 25 years in prison when he is sentenced next month. His was the first trial conviction secured by the newly created hate crime unit of the Brooklyn district attorney's Civil Rights Bureau.

According to trial testimony and court documents, 29-year-old Kimball "Kimy" Hartman was walking on Bushwick Avenue with a friend late the night of Oct. 12, 2014, when Sonds and other men approached and started attacking her, yelling gay slurs.

Sonds then picked up a piece of Plexiglas and swung it at Hartman's head. As she tried to get away, he threw it at her, striking her in the head. Hartman was knocked unconscious, began seizing and suffered profuse bleeding from the back of her head. She underwent surgery to replace a portion of her skull crushed in the attack and will likely suffer permanent repercussions, prosecutors said.

"This defendant, acting out of hate, viciously attacked an innocent woman and left her on the ground for dead," Brooklyn District Attorney Ken Thompson said in a statement. "This was a cowardly, unprovoked and senseless attack on a person who was targeted merely because of her appearance. Today’s conviction demonstrates that we will simply not tolerate bias-motivated violence anywhere in Brooklyn."