A/N: Sirius kills Peter in the street. I had written another story, The Death of Peter Pettigrew, to explain what had happened when Sirius confronted Peter and he escaped. This is a story about Sirius succeeding in killing Peter that day, and the effects his actions have on the rest of the series.

Thank you to SiriusMarauderFan (Lizzy) for helping me think out the plot and coming up with the title.

Submission for:

Was That You? Competition/Challenge: Sirius kills Peter after finding out about the Potters' deaths

Return of the Daily Weird Prompt Thing [Speed-writing Competition]: AU in which Sirius is actually guilty of killing Peter when he gets arrested

Chapter 1 - Catch and Release

Sirius hears the alarms of the damaged Muggle stores and the sirens of the Muggle authorities, but he doesn't care. He stands, staring down at the lifeless body of the person he once called a friend. He had shared a room with him, classes with him, dreams, ideas and hopes, and now he had just killed him.

The rat had tried to transform, to scurry into a nearby drain, but Sirius was too quick for him. He aimed his wand and shouted a curse. Not the one of sickly green; he was too angry for that, full of too much pain and anguish. He wanted the rat to suffer, he wanted the rat to pay.

The spell had caught the traitor straight through his chest, the blood-painted asphalt staring up at him through the large hole. His face is frozen in a mixture of pain and surprise, almost as if he couldn't believe this had really happened to him.

Sirius shouts, screaming at the body, damning the rat for everything he has done, everything he has caused. He brought about James and Lily's deaths, he brought about his own death, he caused Sirius to have to kill him.

Then, Sirius falls to his knees, his dark hair falling over his eyes as he clutches the dead man's crimson-soaked sleeve. He is just as much to blame for this entire mess, maybe even more so. He was the one who suggested switching. He was the one who put the rat in the perfect position to betray them. He was the one who had killed James and Lily. He was the one who had killed his friends.

There are pops now as the Aurors finally appear, the sound of the Muggle authorities still some distance away. They pull him to his feet, away from the dead body, away from this disastrous scene. They are shouting, calling him a murderer, a traitor, a Black. He does not care. He lets them take him, the shackles cold against his wrists as they disappear with a pop.

They appear at the prison in the middle of nowhere, the ocean spray wetting the bottom of his trousers and his face as he stands before the hideous structure. The smoky smell of the burning buildings lingers on his skin but he doesn't notice. He is completely numb as he is thrown into a small cell. In a clearer frame of mind, he would have demanded a trial but what's the use? He is guilty, and his friends' bodies are all the evidence they need. He deserves this.

Within a year, he goes mad. His throat has been rubbed raw from his screams. His skin is stretched taut of over his protruding bones. He is starving but he doesn't want to eat. He wants to die. He wants to pay the price for his sins.

A year later, he is finally granted his wish, as he falls unconscious, never to wake again.