This is a difficult question to answer because there are numerous hypotheticals that can influence the answer. In general, if an individual knowingly made a false profession and was baptized, I would not hesitate to administer a valid baptism. However, if the individual is not sure whether or not they were saved when first baptized I would not ask them to be "re-baptized" because there is no such thing. Many individuals struggle with assurance and that is one of the leading reasons for re-baptisms. Instead, I would explain to the individual what baptism represents.