NEW YORK — A former Rikers Island guard was convicted Thursday of violating the civil rights of an ailing inmate who died after he was repeatedly kicked in the head while restrained on the floor outside a jail doctor’s office.

Brian Coll of Smithtown was convicted in the December 2012 death of 52-year-old Ronald Spear. He was pinned by other guards while Coll kicked him, causing brain bleeding, evidence showed.

Prosecutors said the victim, being held on a burglary charge, had become agitated because he could not immediately see a doctor. Spear had kidney disease and diabetes.

Coll also was convicted of obstruction of justice, falsifying records, and conspiring to cover up the attack.

‘‘Coll killed Spear by repeatedly kicking him in the head as he lay restrained on the ground, telling him before he died not to forget who did this to him,’’ US Attorney Preet Bharara said. ‘‘The FBI investigators and prosecutors on this case did not forget. And today, neither did the jury.’’

Associated Press