Jon Gravelli

is an old school and well connected Mob boss who is currently a patient in Schottler Medical Center. He is introduced to Niko via cellphone through his contact at U.L. Paper who is referred to as a "mutual friend". It is through his and U.L Paper's assistance that Niko is able to have Darko Brevic delivered to him. After Niko has taken his revenge on Dimitri or Jimmy Pegorino, Gravelli passes away in hospital, prior to standing trial.