Why didn't Voldy's soul split off when he killed James? [duplicate]

Question

“You were the seventh Horcrux, Harry, the Horcrux he never meant to make. He had rendered his soul so unstable that it broke apart when he committed those acts of unspeakable evil, the murder of your parents, the attempted killing of a child. But what escaped from that room was even less than he knew. He left more than his body behind. He left part of himself latched to you, the would–be victim who had survived."

_{Harry Potter: The Deathly Hallows (part 7), page 592}

Murder alone doesn't create a Horcrux it takes intent. This section of the book states that Harry is a Horcrux even though not intended. JKR latter said he isn't officially a Horcrux but considering it is stated that this incident is what caused Harry to be considered like one then why didn't the death of James also fracture Voldemorts soul into a third shard that would have flung off to attach itself to someone or something. There were two murders and a third attempted which should have caused three splits of the soul. Now even though he didn't intend for a Horcrux to be made two were made Harry and the piece that Quirell found. Why isn't there another? _{This nicely constructive para added by Kevin on my request to clarify the point...}

OK, so Voldy can't kill both James and Lily with one single spell.

He must have killed James first, then aimed at Harry when Lily came in between.
The reverse can't be true, because the moment he had killed Lily, he would have been destroyed!

So, when he killed James, his soul should have split, or am I missing something?

Why didn't his soul split?

Answer 1

Under normal circumstances, a murder doesn't result in the creation of a horcrux, it simply fractures the soul. It takes a work of dark magic (generally referred to as a "horcrux-making spell") in order to prepare the receptacle and it takes a supremely powerful wizard to be able to detach a part of their (now-fractured) soul from the "master soul" and transfer it to the receptacle.

JKR elaborated on this in a cast + crew interview in 2007:

JKR : The receptacle is prepared by dark magic to become the receptacle of a fragmented piece of soul and that that piece of soul deliberately detached from the Master Soul to act as a future safeguard or anchor to life and to safeguard against death

As to why Harry became a Horcrux, JKR makes it clear that Harry isn't a classic horcrux, he's actually something distinct and different.

JKR: Well, I tell you-- You know what, this will not end the discussion. I know that, and you know that. But here is the thing. For convenience, I had Dumbledore say to Harry, "You were the Horcrux he never meant to make." But I think, by definition, a Horcrux has to be made intentionally. So, because Voldemort never went through the grotesque process that I imagined creates a Horcrux, with Harry, it was just that he had destabilized his soul so much that it split when he was hit by the back-firing curse. And so this part of it flies off and attaches to the only living thing in the room. A part of it flees in the very close-to-death limbo state that Voldemort then goes on and exists in. I suppose it's very close to being a Horcrux. But Harry was not-- did not become an evil object. He wasn't-- he didn't have curses upon him that the other Horcruxes had. He himself was not contaminated by carrying this bit of parasitic soul.

Based on this, the order of events is actually pretty straightforward;

• Voldemort killed James. In the process his soul became 'destabilised'.
• Voldemort killed Lily. In the process his soul became more fractured.
• Voldemort attempted to kill Harry (who was protected by Lily's "love aura")
• The trauma of being hit with his own back-firing curse was sufficient to make a piece of Voldemort's soul escape and infect Harry.