Beagle Killing a Cat

Question
why would my 6 year old fixed male beagle kill a stray kitten when he was raised and still gets along with my cat.  I also have 3 other beagles no problem

Answer
I can imagine how distressing this incident was! I am wondering if you were present when it happened to give me details of what happened that might lend a clue to his behavior. I CAN tell you that beagles have a strong prey instinct and some more so than others.They have an inherent instinct to chase prey. Is it possible that he went after it and then was playing with it and killed it accidently? It would seem like being a kitten it would have tried to fight back which is sometimes enough to deter them. I have a female beagle however who has caught birds and mice and killed them. I don't know that she intended to kill them, more like catch them and then (not being trained in the field) hurt them when she put them in her mouth. A field beagle would have been trained to carry them with a very soft bite grip and not damage them. If you have any more details please write me again.....