Napier was a pedophile who was once Murphy Pendleton's neighbor, which is how he came to know Murphy's son, Charlie Pendleton. He approached Charlie in his van while Charlie was walking home from school and kidnapped him, presumably with the intent to sexually assault him. Napier then drove to a nearby lake where he placed Charlie inside a canvas sack and tossed him into the water, resulting in Charlie's death.
Sometime later, Napier was arrested for the abduction, sexual assault and murder of an eight-year-old boy named Daniel Stephens. Since Napier was a convicted child molester and registered sex offender, it only took the jury four hours of deliberation to return a guilty verdict against him in the Brahms Courthouse. The guilty verdict came with a mandatory life-without-parole sentence. He was immediately remanded to Ryall State Prison by sheriff's deputies, where he was placed in protective custody and began serving his sentence in solitary confinement.
Given Napier's brief appearance at the start of the game and the summary of his character from the rest of the clues in game, it would seem that Napier, like many rapists and pedophiles, has no regret over his crimes. This can be observed through his cool casual demeanor to Murphy Pendleton (before he learned who he really was) and his smug attitude. Napier is also shown to be a coward, as he never fights back when Murphy attacks him.
According to Dr. Wayne Sara, Chief Psychiatrist at Ryall State Prison, "[Napier] does not suffer from any psychotic or physical disorders. Rather, he has shown continually to have an inordinate interest in young children and manifests significant predatory traits. As a result, I feel he poses an imminent danger to the community should he be released from custody, and is therefore a poor candidate for probation."
Silent Hill: Downpour
The death of his son caused Murphy deep emotional trauma, sparking his uncontrollable desire for revenge. This desire led him to steal a police cruiser, getting himself arrested in order to be placed in the same facility as Napier. Once incarcerated, Murphy struck a deal with a corrupt corrections officer named George Sewell. Since Napier was a sequestered inmate, Murphy was unable to have direct contact with him. Sewell orchestrated a confrontation between Murphy and Napier, in exchange for Murphy owing Sewell an unnamed favor.
Sewell tricked Napier into entering the prison shower room alone with Murphy and several weapons and locked the exits behind him. Once the two were alone, Murphy brutally assaulted and stabbed Napier.
Napier makes another appearance as the game progresses. At one point, when the mask of The Bogeyman comes off, it shows the faces of both Murphy and Napier; rapidly switching between the two, showing Murphy's regret over his decision to arrange the fight to begin with. Shortly after, a manifestation of Charlie tells Murphy he killed The Bogeyman, however Murphy responds with the realization that killing Napier didn't do anything, and it was a pointless venture to do so, as Charlie is still dead and it didn't make him any happier in the end.
During the Forgiveness ending, after the fight between Anne and The Bogeyman, another cutscene plays, where Sewell frames Murphy for the assault and near death of Frank Coleridge. Sewell states during the encounter that Murphy was too cowardly to actually finish Napier off, and that Sewell himself killed Napier when Murphy got cold feet after already attacking and seriously wounding him. In the other endings, Murphy did indeed kill Napier. Thus the sequence at the beginning of the game is simply a dream sequence in Forgiveness, or a nightmare flashback in the other endings.
- Murphy's comment on Napier is: "Do I feel sorry for him, for what I've done to him? I keep telling myself he deserved what he got but... the sounds he made... all that blood... the face of absolute terror. Disbelief turned into the understanding of inevitability... all by my own hands... May God forgive me!"
- According to Tomm Hulett, Napier was killed by Murphy in every ending except for Ending A, in which Sewell did it for him. 
- A toy replica of Napier's van can be found in St. Maria's Monastery as an artifact.
- Murphy's dream at the beginning of the game, much like those of Alex Shepherd and Heather Mason, acts as a tutorial on gameplay mechanics.
- In the parking area of the Centennial Building, the player can look through a small peep-hole to witness a shadowy reenactment of Napier's death by the hands of Murphy taking on the monstrous form of the Bogeyman.