There are a lot of people who have already said that they have noted more crimes that occur on Halloween as compared to other events. There is something scarier than the ghosts, goblins, and so much more than you will see on Halloween. It is scarier to find people who are doing other bad things to other people.
There are more people who do crimes on Halloween because they know that it will be easier for them to be in costume and not become recognized when they do certain misdemeanors of felonies. People are also in a more relaxed mood during Halloween and some bad people would take advantage of that.