Six people were actually held prisoner in the scene where Ace and a friend were bundled into the apartment by Calvin's accomplices who demanded the combination. All six were shot in the head when the extortion attempt failed and three died, including Faison's aunt. The real life Calvin, Kevin Clark was not murdered in a revenge killing by Rico, as is depicted in the film. Kevin Clark and his accomplices, Ronald Timmons and Henry Bolden were all arrested soon after the incident and are serving 112 years - to life sentences.
In interviews, Azie Faison Jr., the real life Ace, has repeatedly accused Damon Dash, the film's producer of massively altering and watering down the script for "Paid in Full". According to Faison, the original version presented to Dash was a cautionary anti-drugs tale and social commentary on the destruction drugs have wrought on the black community. Faison has stated that the end result was merely a marketing tool for Dash to promote Cam'Ron a (then) recent arrival to Dash's recording label, Rocafella Records. The rewritten script compresses over 7 years of events into 12 months. Ace is shown becoming a dealer in 1986 but this happened in 1983 after seeing Scarface (1983) and the later events which led to the downfall of all three major characters transpired between late 1989 and 1992.
The trivia item below may give away important plot points.
The scene where Rico (Cam'ron) beats up the guy for saying "so we're supposed to starve cause yo man got popped" actually happened, he really pulled him out the window of the car and really punching him.