Takes place somewhere in the middle of Season 3
Angela Petrelli was too smart for her own good.
He should've thought twice when she decided to 'feed' him, should've asked himself why she would encourage him like that, but no, he'd just given into his cravings and taken the power. Stupid, stupid, stupid. She had even told him what the power was- the ability to see any object's past. He had thought that that would be useful, at the time, and had looked no further. Stupid.
He brushed a hand across the wall in irritation, and was rewarded with a brief glimpse of a previous occupant banging his hands on the same wall, screaming in fury. He glanced over, and smiled grimly at the dents he now noticed. Yes, it could be useful- incredibly useful. But more useful for her than for him.
He hadn't even realized what it would mean, when he found out that he could extend the ability so that it would apply to humans as well. He had been thrilled, in fact, that he could figure out a person's entire history just by shaking their hand or clapping them on the shoulder. True, it did mean that he would be unconscious of his actions for a least five or ten seconds, if he wanted to get the full history- but he was a good actor. He was confident that he could play around it, and gain plenty of useful information in the process.
But when he'd gone for Murphy's ability? He'd been in his best state of mind, focused, pumped with the adrenaline of the hunt. And he'd been excited by the prospect of sound manipulation, as it could go partway in making up for the loss of Candice's ability (which he was still sore about, thank you kindly).
But the moment he touched the man, to determine how the ability worked, the memories started to assault him. Jesse Murphy had not lived a happy life, had not been a good man- he had killed for personal gain, and had killed often. But he had his moments of redemption, and there were a few, far-off memories of his younger sister, a little girl who had looked up to her big brother.
He forced himself to go through with it, anyway; as far as he was concerned, Murphy deserved to die. But he had to live with this man's life, now, and his enhanced memory (which he was starting to regret) wouldn't let him let go of even one of the events. He had to recognize, now, that every killing would be connected to a lifetime, to guilt. He hated guilt. It made him feel… weak.
Angela Petrelli had tricked him well, had found a way to make sure he'd have to think before killing. In a way, it was redundant; he had rarely killed without a purpose before, and had always preferred to go after the unworthy. But he didn't like having guilt forced onto him.
If he was going to 'go good', he wanted it to be by choice, not by his mother's plans.