LV's Choice: Potters or Longbottoms or Both?

[scoutmom21113]

No: HPFGUIDX 99076

Now karenoc1:
...  I'm having problems with the timing of the events. I believe 
that we can assume that Voldemort found out about the prophecy 
*before* Harry and Neville were born. However, he does not attack 
the Potters until one year and three months *after* Harry and 
Neville are born.

Bookworm:
I had a difficult time understanding why Voldemort waited 15 months 
or more – depending on when the prophecy was made - to attack the 
Potters. Finally, I came up with this theory. I may have posted this 
theory before, but I can't find it in my own notes. So here it is in 
a very rough form:

I suspect the eavesdropper was Snape or someone who worked for him. 
But instead of telling Voldemort about it, he used it as his ticket 
to work with Dumbledore. Realizing that the "thrice defied" referred 
to either the Longbottoms or Potters, Dumbledore started to work 
with both families to set up protections using the "ancient magic" 
that Voldemort underestimates. When they were ready (or as ready as 
one can be in a war) Dumbledore told Snape to go ahead and tell 
Voldemort about the prophecy. That's how Dumbledore knew that the 
Potters (and Longbottoms) were in danger and sent them into hiding, 
and why there was a long delay before the attack. 

If Voldemort had heard there might be a prophecy, it was in their 
best interest to have Snape tell him – confirming his cover with 
Voldemort as a spy.

As I said, it's a rough version. Like a many others, I haven't 
figured out why Snape decided to return to Dumbledore's side. But I 
think it fits the canon we do know about.

Ravenclaw Bookworm