91-year-old Robert Nevius was strangled and stabbed to death inside his home in Essex Fells in 2010.
Prosecutors say it happened during a burglary.
Thursday, 28-year-old Shaun Woodson pleaded guilty to aggravated manslaughter and burglary.
Woodson faces 10 years in prison.
A codefendant was found guilty of burglary.
