Packie was born to Maureen McReary and an unnamed father. His siblings consisted of brothers Derrick, Francis and Gerald, with Kate being born two years later. Born and raised in Dukes, he had never been outside Liberty City - except for Alderney State- until after the events of GTA IV.
Packie's father was a violent, perverted alcoholic whom Packie blames for their Mob's fall from influence. He says of his father, "I used to think I loved him, but then I realized I hated him". He eventually admits to Niko that his father used to molest him and Gerald. He developed a drug habit at 14 and claims he was constantly staying home from school to roll joints for his dad.
Packie became involved in crime at an early age, having chosen Gerry as a role model and began spotting for his brother's scores when he was in middle school. His first conviction came in 1997 when he was arrested for stealing a car when he was 18. The following year he secured his first felony conviction when he was arrested for grand larceny but was (presumably) acquitted and was arrested again in 2000 for highjacking. Packie's last known arrest came in 2005 when he was caught with several grams of cocaine in the presence of a known prostitute. At some point his father apparently committed suicide, and Gerry became head of the McReary family although Packie admits that he initially suspected Gerry of killing him.
Grand Theft Auto 4
By the time of GTA IV, Packie largely operates independently of the Irish Mob, committing stick-up robberies with his friends Michael Keane and Gordon Sargent, and working as a hired gun for the Pegorino Family.
Packie was introduced to Niko Bellic through cocaine dealer Elizabeta Torres. Packie and Niko quickly became friends after escaping from a botched cocaine deal together. Impressed, Packie called up Niko and introduced him to his family and his gang. They all participated in robbing other criminal gangs (first robbing the Algonquin Triads and then the Ancelotti Family), and eventually the Bank of Liberty in Algonquin during a heist. Packie purchases a red Comet with his share of the take.
After the bank job, Packie continued working with and befriending Niko, particularly in the kidnapping of Gracie Ancelottifor Gerry. Unbeknownst to Packie, Niko murdered one of his brothers. Nonetheless, Niko's assistance in suppressing an attack on the funeral of the same brother cemented their friendship. Packie trusted Niko enough to encourage him to date Kate, the youngest of the McReary clan. Though he was confident she wouldn't "put-out" - as he regularly states - his bypassing of his protective instinct showed that he held a distinct level of trust in Niko.
In the credits of The Ballad of Gay Tony, Packie is seen exiting a taxi cab and entering the airport with a duffel bag, presumably filled with money. In the following scenes, a plane is seen leaving the runway headed for an unknown destination. By 2013 he had settled in Los Santos.
Grand Theft Auto 5
Packie appears again in Grand Theft Auto V, popping up rather early in the game as he robs a drug store in Strawberry with an un-named accomplice. Once you find him, he requests that you find a getaway car and help them escape. You may do so, or assist the store owner and kill Packie and his accomplice. If you commit to the former, he will thank you and become available as a gunman in further heists. Packie has some of the highest possible skills for a gunman available, but takes 12% percent of the cut.
Interestingly, Packie mentions his biggest robbery during The Paleto Score, if he was chosen for the job. On the way to the bank, the gang will talk about their first robberies. Packie mentions that one of the gunmen were killed by one of the hostages, and goes into detail regarding how they escaped. He will also mention his brother, Derrick, who was also a gunman in the Liberty City robbery, and say that he is dead. Lastly, he mentions Niko Bellic, the fourth gunman. Packie says that he had lost contact with Niko after leaving Liberty City, and that he doesn't even know what became of him, presuming him dead.
- Lester Crest: "McReary? He was a part of a well known Liberty City stickup crew. Small world."
- Michael De Santa: "I got a good feeling about him."
- ―Lester and Michael about Packie.
Packie can be selected in all the heists of the game. In The Jewel Store Job, smart or loud approach, he manages to get all the jewels in the glass cabinets, helping the crew reach the maximum possible score of the job. In the loud approach, he also stops the manager of the jewelry store before she screams for help.
In The Paleto Score, Packie survives the heist and provides a good help against the cops. Michael even compliments Packie's help by saying that he is glad they choose him for the score.
In The Bureau Raid, he survives the explosion during the escape in the covert approach and in the roof approach, he does a good job with no consequences.
In The Big Score, subtle approach, if placed as one of the gunmen, he does not drop any gold bars while he is loading them into the Gauntlets, preventing the crew from losing any of the final score.
In the obvious approach, if he is selected as either the first or second gunman, there are no consequences to the heist. Previous experience in past heists won't change Packie's performance in any of the scores; he does a good job in all of then even if he is selected for the first time.
On the surface, Packie portrays himself as strong and without feeling. But when drunk or otherwise confiding in Niko, he is shown time and time again to be suppressing deeply painful emotions. For example, he will lament that "the world is ugly and unkind", question what being a man is all about, and contemplates suicide. He has an addictive personality, as shown by his habitual use of cocaine and prostitutes. He doesn't seem to seriously consider immediately and directly killing himself, but does glamorize the idea that he will die young of drug overdose. Compared to Niko, Packie is equally capable of violence and criminal activity whilst appearing to show little or no remorse. He does, however, still hold certain moral standards; if the player kills too many hostages during the mission Three Leaf Clover, the mission will fail and Packie will say that he doesn't take "bloody money".
Packie's cocaine addiction has caused him numerous problems. He claims that he can't look for women without cocaine in his system and when he's with women, he spends his time in the bathroom snorting rails of coke, which lowers his sex drive (he calls this a "catch 22"). Kate claims that Packie has uncontrollable behavior when he's with her in public and will attack anyone who he thinks is looking at her "wrong".