re-raise something like 3.5x his bet, you can put him on a range like AK, AA, QT, KK,JJ,55,KJ,K5s and maybe J5s. I think that it`s likely that he shoves with all of the above.
You are ahead of AK (8), AA (6@70% equity), QT (16 combos around 70% equity), K5s (2 combos). You are behind KK, JJ and 55 (7 combos). Getting it in now is perfect, as you are definitely getting called by AK,AA and K5s, and even more bad hands. Getting it in now prevents you to get sucked out especially if he has QT. Of course, he could be bluffing, but it's unlikely since he's betting into 4-people.
Did he have a set? That's a cooler