If Beale Street Could Talk Ending Explained (Spoilers)
To combat Officer Bell who pushed Victoria into fingering Alonzo with raping her, Sharon needed Victoria to stand trial. Her being in Puerto Rico, where she ran off to, would mean all the courts would have is Officer Bell’s testimony, and with him being a cop, it would be over for Alonzo. Yet, due to pushing her too far, Victoria ended up disappearing once again and leaving Alonzo without the hope her recanting could have given him. Hence him taking a plea deal so that, rather than the trial being delayed over and over, he’d get a sentence and could begin counting down to freedom. One which wouldn’t come for years, past the point his son could talk and walk, maybe be in school, but at least he knew there would be a set date he’d get out.