One more thing. Whenever its possible try to find your own references. The ones given will not always give you the truth (for positive and negative).
(If you are looking into someone from a different place, call someone who can connect you with other people, even someone you don’t know, and just ask for the name of a rav in the area, or someone who would know people in the community. You don’t need to get into names, but usually when people hear its for a shidduch they will try to be helpful.)