The following contains spoilers Punisher #5, now on sale from Marvel Comics.
The Punisher is one of the most dangerous individuals in the Marvel Universe, with plenty of casualties under his belt from all around the world. But each and every one of those deaths can be quietly traced back to the moments that led Frank Castle down his violent path, especially the presence of one crucial figure in his life.
Punisher #5 (by Jason Aaron, Jesus Saiz, Paul Azaceta, Dave Stewart, and VC's Cory Petit) reveals that the seemingly insignifant life of one of Frank Castle's earliest friends played an important part in putting the gun-wielding vigilante on the path to becoming one of the criminal world's most feared opponents.
The new Punisher series has been quietly revealing more and more details about Frank Castle's early years, delving into the circumstances of his earliest kills. By the time he was a teenager, Castle had become a very unsettling young man, with both the student body and faculty all terrified of him. However, young Frank found an unlikely friend in Steadman Sternberger, a nerdy figure who was often the target of bullies. Castle inevitably became a protector to his friend, using his inner rage to scare off prospective bullies. At the same time, Frank now had a friend who consistently did his best to urge the future vigilante down a more constructive path.
Steadman's influence resulted in Frank joining the local hockey team and gaining the acceptance of his peers. This, in turn, eventually led to Castle meeting Maria Falconio at one of his games. Noticing that Frank seemed to like the girl but was too shy to speak with her, Steadman took the initiative to tell her about Frank's feelings and write her a love note (claiming it came from Castle). This set the stage for their romance, eventual marriage, and the birth of their children, which was tragically followed by the deaths of all of them but Frank, transforming him into the Punisher. Steadman had no idea of the impact he had on Frank, hanging out with other groups until he was ultimately killed in a car crash.
Steadman's brief life and tragic death might seem like minor pieces of the overall puzzle, but they're actually crucial steps that Frank needed to take before becoming the Punisher. Without Steadman, Frank Castle might not have even completed high school without getting expelled or entered the military, where he picked up a plethora of deadly skills. Without Steadman, Frank wouldn't have begun a romance with Maria or gained the family that he'd pathologically need to avenge by becoming a vigilante. Without Steadman, Frank would never have figured out how to channel his fury into the new endeavors that eventually led to him becoming the Punisher.
Steadman wasn't the sole impetus that drove Castle down the road to becoming a vigilante, but he was a crucial part of setting up the circumstances that led to his change. It's even implied in the issue that the demonic force known as the Beast may have manipulated Steadman's meeting with Castle (along with his eventual death), making him the sacrificial lamb slaughtered by a world that needed the Punisher. In light of his death and discovering the young men who abandoned Steadman to his fate, Castle is heavily implied to have murdered them, further pushing him down the dark path that led to his present day persona. In a franchise where series like What If...? have explored the ramifications of minor changes to history, it's worth noting how this simple friendship can be directly tied to the multitude of deaths that would later be caused by the Punisher over the years.