Answer to this question , cannot be known thru speculation ,logical conclusion , opinion etc as it is beyond any human scrutiny. ( so the ans. cannot be to the point , but tangential)
In light of scripture s (to my knowledge ), .. The person who is sinner/virtuous at a point in time , acquires a karmic blue prints for sowing such intentions / actions, which is sure to produce an inevitable effect that needs to be reaped, ..May be it could fetch a jiva a new birth conducive to reap it's effects(Amushnika phalam) or it may reap in the same life.
(when , where , how cannot be guessed)
Satapatha Brahmana says-
A man is born into the body that has been made for him (6.2.2.27)
(Sri SN Saastri)
tat tatra yathaa raajaanam...
Just as, when a king visits some place within his kingdom the leading citizens of that place, as well as certain others appointed by the king to perform specific duties, wait for him with food and drink and a palace kept ready for his stay, similarly, for the transmigrating self who is about to take up a new body, the elements that are necessary for the creation of that body, as well as the presiding deities of the organs, such as Indra and others, wait with the means of enjoyment of the results of his past actions, saying Here comes Brahman, our enjoyer and master
(Br.up.4.3.37, Sri Shankara Bhaashya , Translation Sri SN Saastri)
tatra asya idam sariiram parityajya..
Now a question may arise---- When the jiiva goes leaving one gross body, he has no power to take another by himself. Nor are there others who, like servants, would wait for him with another body made ready, as a kings retinue waits for him with a house kept ready. How then can the jiiva get another body? The answer is: He has adopted the whole universe as his means for the realization of the results of his actions. Therefore the whole universe, impelled by his work, waits for him with the requisite means for the realization of the results of his past actions
(Br.up.4.3.37, Sri Shankara Bhaashya , Translation Sri SN Saastri)