24-year-old Caleb McGillivary remained silent Monday while his public defender entered the plea in court in Elizabeth.
McGillivary is accused of killing 73-year-old lawyer Joseph Galfy, whose body was found May 13 in his Clark home. McGillivary was arrested in Philadelphia days later and could face a life sentence if he's convicted.
Authorities say the two met in New York City and McGillivary stayed at Galfy's home.
The Canadian gained some online fame after intervening in a 2012 assault on a California utility worker in which he described using a hatchet to fend off a further attack.