A mistake by a superior court judge may set a Georgia man free without him ever having to stand trial.

Geary Otis is accused of killing a 75-year-old woman and injuring a 71-year-old man at an apartment complex for seniors in Atlanta in June 2013.

His lawyer told a jury Otis "just snapped" and asked jurors to find him not guilty by reason of insanity. Prosecutors objected, saying they hadn't gotten prior notification of the insanity defense.

The judge said the law required the prior notification and declared a mistrial over Otis' lawyer's protest.

The state high court ruled Monday that the judge had erred. Prosecutors will ask the justices to reconsider. If they don't, Otis could be freed in a few weeks after spending nearly three years in jail.