There's some background information at Wikipedia -Since this is a JJ Abrams production, who knows when they'll give us enough of the backstory. Obviously how Finch was crippled is one of the mysteries, but I'll bet it was violent so I'm surprised he's so much of a pacificist, or perhaps that is why. I think i remember the bust and assumed it was of Finch.
Harold Finch (Michael Emerson): A reclusive, intensely private billionaire software genius, Finch developed a post-9/11 machine that can isolate the social security numbers of people with either premeditated homicidal intent or who will be homicide victims, based on its analysis of surveillance video. Following a traumatic event in his own life that lead to the death of his business partner, he recruits Reese, whom he addresses as "Mr. Reese", to help him deal with the people the machine identifies. Finch lives and works in an abandoned library, and shows the results of severe physical injuries, including the inability to turn his head, rigid posture, and a limp.
Nathan Ingram (Brett Cullen): Finch's deceased collaborator on The Machine. Ingram acted as the interface between the government and their company while the machine was under development. There is a memorial bust of him in the headquarters of their company.