Tipu bhai,
The best thing to do is to thoroughly observe (or if you already know it from experience) their character/values as a family. Also try to see if the guy loves your daughter as well, and how's he as a person. Hopefully he's pursuing the relationship with a clean heart, and in that case you won't see much trouble from his side in the future insha'Allah.
You must also find out if that family is in the favor of this rishta. Are they even willing to come forward? how do they behave in conjunction with the old issues?