A deaf Melbourne man who murdered another by pushing him off a balcony, but was unfit to stand trial, will spend 25 years in custody.

Last year, a jury in a special hearing found Jake Fairest, 27, and friends Warwick Toohey and Georgia Fields murdered Robert Wright in 2015.

Jake Fairest will spend 25 years in custody for the murder of Robert Wright. Credit:Jason South

Fairest, Toohey and Fields are profoundly deaf, as was Mr Wright, who also had epilepsy and cerebral palsy and reduced functionality in his left leg.

Fairest was on Thursday given an indefinite custodial supervision order, with a nominal period of 25 years, at a residential facility run by the Disability Forensic Assessment and Treatment Service.