Like in different chapters when he sees Hester in the scaffold he is the victim. When Hester came down from the scaffold and Pearl was alterated. He came in to the the jail and told the guard that he fas a Physician known as a doctor and the let them in. And help Hester to calm down, he gave them a sedative to calm them. That reflects that he was a good person until he starts getting clues about , did that to Hester. He asks her who did it but she wouldn't reveal it. He says that he would fin out who did that to Hester but still she wouldn't reveal who was it.(Hawthorne)
Everybody thought that Chillingworth would stay the same since the beginning of the Novel nobody thought that he would change. When Dimsdale started to act weird when he sees that Chillingworth was looking for the person that got Hester pregnant. He was looking for revenge. When Dimsdale really got shocked by the depression and they assigned Chillingworth to stay with him and take care of Dimsdale. Chillingworth started looking for clues if Dimsdale was who got Hester Pregnant.