John Reese is a fictional character and the main protagonist of the CBS crime drama television series Person of Interest.

He works with billionaire Harold Finch to help residents of New York who are potentially involved in violent crime.

Extremely skilled with a range of weapons and combat techniques due to his military experience, Reese possesses a level of determination that drives him to work with Finch to protect potential victims of violent crime.

While he was stationed at Fort Lewis, Washington in 2001, John met Jessica Arndt, a nurse with whom he fell in love.

On a vacation to Mexico, he tells Jessica that he has left the Army just as they witnesses the Twin Towers fall on television and he decides his military career is far from over.

Although Reese demonstrates the skills necessary to conduct the missions to which he is assigned, he shows some hesitation to commit fully to them as he lacks the ruthlessness shown by Kara.

During a mission hiatus, intelligence officer Reese encounters Jessica's spouse, Peter Arndt, at a clandestine establishment.

Years later, amidst a Middle Eastern deployment, Reese receives a voicemail from Jessica requesting urgent contact.

Their mission is to enter an abandoned Chinese city and recover highly sensitive computer files on a laptop.

Prior to extraction, Reese identified a possible shift in mission parameters; the retrieval of the data device may have been a secondary objective, with its eradication taking precedence.

This suggests a potential compromise within the agency, with both operatives targeted for elimination to prevent unauthorized access to sensitive information.

[1] Reese then returns to New York City and drops off the grid entirely, living first in a homeless encampment[4] and later a SRO[3] until he is sought out by Harold Finch.

"After Jessica's death, Reese begins living as an unkempt vagrant on the streets of New York, attempting to escape from his demons with alcohol and martial arts movies.

As their first case progresses, Reese discovers corrupt police are involved, and realizes he's in a more complex situation than he expected.

They walk through a park and Reese listens as Finch tells him about a complex computer called "the Machine", his role in its development and how it creates the relevant and irrelevant lists to find potential criminals.

With more information and an stolen identity based on a badge taken from NYPD Detective Stills, a corrupt cop whom he killed in action.

Once the case is closed and having enlisted the reluctant assistance of Detective Lionel Fusco, Reese now fully commits to working with Finch.

Finch is more reserved, but spares no cost or effort to save Reese's life when he is shot by a CIA sniper.

With the entry of Harold Finch into his life, Reese undergoes a series of wardrobe changes that help to earn him the moniker "The Man in the Suit."

Possessed of some money despite his vagrant lifestyle, Reese is able to get a haircut and purchase clean clothes following his first encounter with Finch, first a tee-shirt and jeans, then a dark shirt and leather jacket he wears for his first day they work together.

According to the legend, a tall, nicely dressed man in a suit often shows up unexpectedly and always in time to halt a violent crime from happening, saving innocents and injuring perpetrators, to varying degrees, in the process.

Guided by direct contact with the Machine, Reese holds off the Samaritan agents but is gunned down moments before a cruise missile destroys the building.