Hazrat Shaikh Moulana Muhammad Zakariyya (rahmatullahi ‘alaih) once mentioned:
It is incorrect to prejudge any person without first investigating the matter. If you hear that a certain person is a thief, then out of precaution, it is safer for you to not allow him to enter your private room. However, without first investigating and verifying the information, do not pass the verdict that he is a thief nor call him a thief. This important principle of Deen should be borne in mind and adhered to at all times. (Suhbat Baa Awliyaa pg. 135)
Source: Ihyaauddeen.co.za