I'm gonna go with 4.5 based on the fact that all you have are a couple pics at midnight. Three year olds will still move around some in daylight. His body confirmation could go either way. Good luck with him this fall.
Not the best picture for aging, but this one does show his belly sagging below his nut sack. The lack of chest depth is what has me perplexed. But I've about decided I'll shoot him if I see him. And I guess that's all that really matters.