Hurting pets is one of the well-known 'red flags' of an abusive person. It's surprisingly common. 
It doesn't normally extend to killing an animal though. It cannot have been accidental if there was a five year ban, though this does assume that the newspaper has the story correct. (It's also one of the clinical indications of a psychopath, but that's another story.)
Either way, anyone who deliberately kills a kitten is not someone who values life or has any empathy. This is a person who may well seem capable of expressing love and tenderness when it suits him but it's all false. As soon as you challenge someone like this, that coldness will be turned in your direction.
The proportion of abusive men who change their ways is about 5%. What are the odds he's one of the 5%? He's already been abusive and has anger problems. The facts are speaking for themselves really.
MadFool I'm so sorry you've just been hit with this. You must be feeling shell-shocked, even if deep down you already had suspicions about his behaviour. 
Is there anywhere you can go? Can you go stay with a friend and leave a note on the kitchen table that there's been an emergency? Use the time to find out more, if possible.
I really don't think you should confront him with this right now unless you can have someone there to support you. It's possible he'd just break down and cry, but it's equally possible he'll be furious and take it out on you simply because you are there.
If you go to stay with someone, I also don't think you should tell him that you know until you are ready to have that conversation with him. If it is true if you let him know beforehand he will use the time to come up with some very plausible excuses that will have you doubting your own mind, let alone a newspaper report.
I'm so sorry and hope you get some support to deal with this.