Evidence 1: Charlie didn't think before he fired at Pete Van Horn and killed him.
Theme: Don't jump to conclusions
Evidence 2: Everybody was assuming the other people were monsters and started getting a little upset and violent.
it was You!
It was him!
Evidence 3: When Les Goodman got out of hiss car and turned his back and it started, everyone thought he was the monster.
I'm just as surprised as you are...
One of the main themes of The Monsters are Due on Maple Street by Rod Serling is din't jump to conclusions. Here are some reasons why, The first evidence is Charlie didn't think before he fired at and killed Pete Van Horn. This shows because Charlie thought that Pete Van Horn was a monster and didn't try to communicate with it to see if it was human, he just snatched the shotgun and killed Pete. The second evidence is Everybody was assuming one of the other people (or family) was/were the monster(s) and started getting a bit violent. This supports the theme because nobody was using common sense, they all thought that the monster was one of them, it could have been someone (or something) else. The third reason is When Les Goodman's car started, everyone thought that is was suspicious and started thinking that he was the monster. This evidence supports the theme because everyone just assumed that Les was the minster because the car started, it could have been anyone who started the car and not Les. Those are the reasons (or this is the evidence) that support one of the many themes of The Monsters are Due on Maple Street.