Thank you for all the opinions and experainces.
He was raised with other rats, not by himself. I had him in with 2 young females since I recently acquired some new rats. I put him back into the bin with those 2 young females. He will get a chance to be with them in the bin for their first litter and see if he harms the babies then. If so, he's a goner. There's entirely too many male rats available at that point.
The odd thing is that I remembered late last night, I had gotten another new young male, nearly identical to him, but from another source, and put HIM in with a different bin(prior to the mauling incident). That bin also had babies, but those babies were big enough to have just gotten fur on them. He has shown no desire to hurt babies. Of course, I don't know if he's simply more timid, those females are more protective, or the babies being big enough to have fur is the reason behind his 'kindness' towards the litter.
At any rate, it's a learning experiance and next time I will wait to place any new male into a bin of females until there's no babies in the bin. I appreciate the discussion. When I kept rats before I didn't have too many issues.
And for females with first litters, I always give them leeway on the first litter. It's when they continue to kill their babies that I cull them. New moms that have undue stress due to moves or any strange incidents are likewise given leeway. That's why I was unsurprised when two litters were killed so soon after I got the colony and moved them, shuffling all the rat groups around, since I had no way to know which rats had been grouped together.