If someone claims another person they know or dated stalked them and looked into their windows shouldn't they have taken pictures of the person looking into window or by house or claiming just walked into house locked the door?
If this is a legal case, the plaintiff should provide evidence or witnesses. Otherwise, anyone can claim anything.
Then, if the defendant has a history or record of breaking the law, that could be taken into consideration but they will be warned or could get a restraining order issued against them. It shouldn’t be any serious punishment without proof of stalking.