He says that's the length of a life sentence according to a law that was on the books from 1974 to 1978. The law reads, "a life sentence shall be considered as 80 years."
"It says what it means, and it means what it says in the clearest and most direct terms possible," explained Bowden's attorney Jane Allen.
But a prosecutor from the Attorney General's office argued that two words make the old law ambiguous.
"Considered as," Bill Hart told the justices.
Several justices, including Robin Hudson, questioned that logic.
"What else could it mean other that 'treated as' or 'think of it as'?" she asked.
"Life sentence, a life, life imprisonment 'is' 80 years in prison, or life imprisonment is 'defined' as 80 years in prison," Hart answered.
Hart argues that the 80 years refers only to eligibility for parole review not release from prison.
If Bowden wins, as many as 120 inmates could be released immediately or in the near future - many who have already been turned down for parole.
"Should the law be interpreted differently and they were to be released suddenly with no supervision, that'd be a concern to us and probably should be a concern to the communities where these people are gonna go and live," said NC Dept. of Correction spokesperson Keith Acree.
The justices do not announce when they will issue a ruling. It could come as soon as three months or be longer than a year.