In time, after learning of his tragic birth, the young Sullivan gradually started to believe that Room 302 itself was his mother, and the child started making weekly trips to Ashfield to visit "her," much to the dismay of the apartment's current residents. During his late adolescent years, he learned of the "21 Sacraments," an obscure ceremony in the Order's teachings that Walter could use to "awaken" his "mother."

Sometime later, he briefly encounters five-year old Eileen Galvin while homeless. Eileen, out of sympathy, gives the perplexed Walter one of her dolls then walks away conversing with her mother. The scene of Eileen happily walking with her mother, while he holds her doll in hand, inspires a profound sorrow within Walter to which he sobs uncontrollably.

When Sullivan was 24, he began his killing spree, murdering 10 people in as many days, removing their hearts and carving numbers into their bodies. The first corpse had 01121 carved into it, the second 02121, the third 03121, and so on up to 10121. He made no effort to cover his tracks, even going as far as to carve his own name into the flesh of his victims. He was captured, tried, and convicted, and was thought to have committed suicide by stabbing himself in the neck with a metal soup spoon and severing his own carotid artery while in prison. He was buried in an unmarked grave near the Wish House, however, three days later, a man fitting his description was seen exiting Room 302 of the South Ashfield Heights apartment building.

Three years later, another body was found, killed in a very similar manner to Sullivan's previous victims, and the numbers 12121 were carved into the body. The police suspected a copycat, though the heart was not removed, nor was a name carved into the body. However, Joseph Schreiber, an investigative journalist, developed his own theory at this time. He believed that the police had failed to capture the real Walter Sullivan, and began to investigate Walter's life in conjunction with an earlier investigation into the Silent Hill cult. Eventually finding Walter's grave, Schreiber discovered there was no body inside and that numbers, 11121, were carved into the coffin. Two more bodies surfaced over the next few weeks, carved with the numbers 13121 and 14121 respectively. Joseph Schreiber went missing from room 302 shortly thereafter. What the police failed to realize was that the numbers, 01121-14121, actually meant 01/21-14/21, meaning that Sullivan intended to kill 21 victims in all.

JOSEPH SCHRIEBER (Voiced by 'Robert Belgrade')

An investigative journalist who was investigating the Sullivan murders and the Wish House prior to the game. Joseph is the former resident of Henry's apartment and Sullivan's 15th victim. Before the game's events he disappears, the exact circumstances of his presumed death are never clarified, and he appears in the game as a friendly ghost offering advice on how to defeat Walter. A salute to Silent Hill 3 in which Joseph's "Wish House" article was found by Heather at the 1st floor of Brookhaven hospital, saying she "knows that place from somewhere."