So I DM a homebrewish campaign for my friends (there's 6 total in the party) and one day we were having an adventure until this "cool, great adventurer" looking guy comes up and asks us for help. So here's the back story. There's an evil group using on of the big churches to gain power. And they send adventurers to go do bad things/to their death. Anyways, my party listens to this guy (He got high persuasion rolls and the party basically failed) and they get sent to a village. The guy claims that the village is evil and is full of terrorists that will attack a nearby town. So they listen to him and go to the village, while ignoring my vague warnings as DM. So they get there and murder 1 sleeping family quietly. I say murder because they failed stealth rolls and woke most of the family up. So then they split up (there was four of them that day so they went in two groups of two. One stayed back to loot and the others went to kill.) They murder everyone in another house. But this is where I start messing around with the characters. They realize now that they have been killing children too. I don't know how they missed that detail but you know. Anyways, group 1 (the one that stayed at the beginning house) found notes written from the children to their mother telling her that they love her. At the time that hit pretty hard. But group 2 had no clue. Group 1 also found an eviction notice from the evil church group I mentioned earlier. Group 1 starts to get suspicious. Group 2 goes to another house and murders everybody. Except for one kid who wakes up. Turns out he's blind and thinks the blood on him is a leak in the room. So the paladin goes for a "non lethal blow" and lands a 20. BUT because she was a paladin I had to punish her for her actions. She just killed 2 families and this kids family. So I made it so the kid basically blew up. Yeah that had a toll on them. Group two then goes to the fourth/last house. It looked run down and shady and there were barrels all around the house. They kick down the door and... Realized that it was trapped. The barrels were filled with gunpowder and blew up. Group 1 meets up with group 2 and they all think that they betrayed each other. After them fighting for awhile they go back to find the guy who sent them here. He killed himself before they could get to him and couldn't get anymore information. They fell for the plan and are now wanted people.
Anyways, here's the death count of people they killed that day:
Parents:6 Kids:12 Grandparents:5 Guards: 4 And one dog for some reason.
TL;DR I DM and my party fell for a trap and killed innocent people.
I'm sorry about how messy my post is. I don't post on reddit much.