|“|| Do you remember when I told you sometimes you must do things, and not ask why? Well, this is one of those times.
Adam trained at Fort Benning in Georgia. He was part of the XVIII Airborne Corps, and he was stationed at Fort Bragg in North Carolina. He was a former military man of 15 years - a Colonel in the American Army, eventually retiring.
Throughout the course of events in Shepherd's Glen and Silent Hill, the Shepherds' connection to the Order is revealed, as is their role in the ritual that demands a sacrifice every 50 years to satisfy their god. However, after finding a letter from his father, Alex learns of his father's decision to confront Silent Hill and disregard the sacrifice in order to save Shepherd's Glen.
Throughout his children's childhood, Adam was viewed as the disciplinary figure of the Shepherd household and showed a peculiar favoritism for Joshua over Alex. This can be seen in Alex's house upon returning home as there are virtually no photos of Alex throughout the house. There is a cassette tape that Alex can use in the answering machine in the kitchen. The tape contains a recording of Adam coming upon the boys as they imagine they are recording a radio program. Yelling at Alex and forcing him to leave the room, Adam then berates Joshua for taking part in what he perceives to be foolish make-believe. Adam then proceeds to explain to Joshua that it would be best to let Alex hang out with his "own" friends, and that if Joshua ever needed a friend, he should come speak to his father and consider him a friend instead of Alex. Adam also disliked Alex and Joshua watching too much TV all day.
Silent Hill: Homecoming
When Alex arrives home, his mother simply comments that Adam went "looking for Joshua". Alex "encounters" Adam many times throughout the game through multiple flashbacks, but actually and unknowningly first finds his father in a confession booth in the Church of the Holy Way, where he confesses (to someone he believes to be a priest, but is actually Alex) that he loved both of his sons and did not want to lose either of them to the sacrifices required by the cult. He admits to treating Alex badly because he knew he would be sacrificed thus not wanting to become attached and lessening the blow when the time came. Alex's choice to forgive or not affects the game's ending.
He is later seen in the same church, strapped to columns in front of the Order's lair. He then explains that Alex was not in a war and was merely delusional after his brother's death. Because of his mental condition, Alex was instituted in a mental ward. Alex, in disbelief, does not believe his father, to which his father does not blame him. After apologizing to Alex for his horrible childhood, he is executed by the Bogeyman, tearing him completely in half with his Great Knife.
Near the game's conclusion, Alex learns of Adam's decision to offer him as the family's sacrifice but whose eventual failure to do so lead to the events that cursed Shepherd's Glen. It is here that Adam reveals to his son that despite Alex's memories of being treated badly by his parents, his father had always loved him, just as his mother revealed just before her death. However, knowing that they had to sacrifice their son, they had to make the hard decision to not show Alex any love, in fear of finding the sacrifice too difficult to make. It's through irony that the events occurred regardless of this detachment.
In the "In Water" ending, Alex awakens in the bathroom, and his father Adam appears and says that Joshua can continue the legacy and then he proceeds to drown Alex. This shows that Joshua is alive, and Alex, shouting "No!", is sacrificed. This could possibly indicate Alex's insanity.
- "I have failed, and they know it. They blame me. They should. I swore to protect this town, but I can't. The streets decay before our eyes. The curse we always feared has come upon us. Worse yet, the Order has returned, kidnapping and killing with impunity. Brainwashing those they take in an effort to rebuild their flock. Whether they want to punish us for the exodus of our forefathers - or simply breathe new life into the old ways, I don't know. But they've taken our people. The only thing left is to face the source of this evil, to fight it, and pray that some hopes can be restored. My sole consolation is that I've finally opened my eyes to the evil in Silent Hill."
- "I took my role as a father and I turned it into a daily chore. I fed him, I cleaned him, I put him to bed. I treated my dog with more respect. And when I was given a second son, the first might as well have been a stranger sleeping in our house."
- "What the hell are you doing? You know this place is off limits. I don't ever want to see you in here again! Are we clear?"
- "You hate me. It's okay. I don't blame you."
- "I never meant to hurt you, son. I had to make a choice, and now I'm paying for it. We all are. After all I've done, you still wear my old dog tags... that must mean something."
- "Alex, forgive me."
- "What have you done? It wasn't supposed to be him. I chose you."
- "Don't be afraid, son. Your sacrifice will save us all. Joshua will be safe to carry on the family name." (before drowning Alex in a bathtub)
- He is voiced by Al Bandiero, who also voiced Curtis Ackers in the same game.
- It is likely that Rebecca Anne Shepherd was his sister, who died not long before Adam was born. This would also make David and Martha Shepherd his parents.
- In the first few seconds of the game, the surgeon who is pushing Alex's gurney in his nightmare is Adam. When he and Alex are in separate rooms, the surgeon is seen being slaughtered by the Great Knife; this is a foreshadowing of the Bogeyman slaughtering Adam, which occurs later on in the story. Later, in the Otherworld hospital, Alex finds the surgeon's corpse split in half, which is also ominous of Adam's fate. This act of foreshadowing is even so accurate as to include the fact it was the right side of the corpse that contains the surgeon's head, just as when Adam truly dies.
- Adam was slaughtered by the Bogeyman twice in the game. In the same way, James Sunderland watched Maria being killed twice by Pyramid Head in Silent Hill 2, although Maria actually died twice in the Fog World, while Adam was killed only once in reality.
- It is stated on his dog tags that Adam's blood type is type O negative.
- Through examining the Shepherd house and also in a flashback, it becomes very clear that Adam is both an avid hunter and fisherman. Duplicate pictures of a mule deer buck as well as a whitetail deer doe can be found throughout the house, and on the second floor, just prior to the entrance to the attic, a whitetail deer can be found mounted on the wall, as well as antlers. To the left of the mounted deer, a species of bass fish can also be seen.
- Early in development, Adam was considered a likely candidate as a playable character for lost episodes of the game, in which the player would explore what happened before Alex's arrival in Shepherd's Glen. This however, was refuted by Tomm Hulett who stated there was never any DLC planned for the game discussed at Konami. 
- In the basement of the Shepherd house, a silhouette of Adam standing can be seen behind a curtain. Cutting through it reveals that it is just a mannequin.
- It is unknown how Adam would be able to go from being in the confession booth to being tied up, ready to be executed, in the matter of minutes it takes to travel between these two places. While this may have been a simple goof by the developers, it may also suggest that Adam wasn't physically in the confession booth, but mentally there to confess his sins. It's all up to the player's interpretation.
- Adam's death is censored in the Australian version of Homecoming. When Adam is later cut in half by the Bogeyman, as the camera pulls back to reveal the scene, his remains have completely vanished. The player can still examine the scene, and Alex will still comment "Dad's remains", despite there being none.
- Both Adam and his wife die by being separated into two pieces; Adam dies by being sliced in half, while Lillian dies be being torn in two. This is symbolic of both of them being "torn in half" between their two sons.
- One of Adam's concept art (below) was referenced by Terry O'Quinn's character "Locke" from the television series Lost. This can be proven in the details, such as the veins on the hand and the folds of the shirt.
- Unused text in the game reveals a comment from Alex about his father: "I can't believe he was still alive, after all that. He wanted forgiveness. Well, he can't have it. Repenting on your deathbed doesn't make up for a lifetime of neglect. I'm sorry, but too much has happened."
- Tomm Hulett revealed in an interview that Adam used to train Alex, and this is the reason Alex is better at combat compared to previous protagonists, despite never being in the military.