The other girls that follow Abigail’s lead share some of the responsibility.
I find the most fault with Reverend Parris who has a moral obligation to find out if the girls are telling the truth. He lets himself get caught up in the mob hysteria and thinks more about his status than he does with doing the right thing. Being an adult and the religious authority of the town, he has the ability and clerical or moral authority to stop the accusations and trial at any time. He does not.
Danforth is more concerned with the reputation of the court than looking at the case objectively. Danforth reasons that if the accusations have all been false, it would reflect badly on the court. Hale is on the fence. When he arrives in town, he is relatively objective. In the end, he bends to the conformity of the town.
You could also blame the town as a whole. There are some examples, people like Giles Corey, who stand up to the hysteria and think objectively. But the majority of the town just goes with the flow. The town has a social, collective responsibility and they fail miserably.
If I had to pick one person, other than Abigail, it would be Reverend Parris because, for the reasons I mentioned.