Three Cats, one won't use litter box.?

I have 3 male cats, all of them are fixed. Murphy & Fletch are litter mates & are a little older then a year. Newman is 3 years old who used to live in a flower shop. But after he playfully bit a customer, they decided he needed a new home. We took him in almost a year ago. For the past 4 months, he won't use the litter box & it's always in the same place, our hallway! I've tried several different types of cat litter and have the biggest cat box I can find. I don't want to resort to having 2 cat boxes. Any advice?