A gangster turned vigilante who’s no closer to finding his son’s killer after years of searching, gets new information from an unlikely visitor – the son of one of his past victims – but the info comes at a price…

A variation ....... A former gangster is reinvigorated , when a unexpected witness reveals a vital clue to his son ' s death , but when the motive is revenge it ' s personal .

sorry...typo. here goes:

A self-righteous vigilante, no closer to finding his son's killer after years of searching, gets new information from an unlikely visitor ? the son of one of his past victims ? but the intel. comes at a price?

refined:

A self-righteous vigilante, no closer to finding his son's killer after years of searching, gets new information from an unlikely visitor ? the son of one of his past victims ? but the intel. comes at the a price?

(do I need to say the price, or can I leave some mystery?)