Secrets (Long) OLD POST REPOST

[Carol]

No: HPFGUIDX 186527

Carol earlier:
<snip> 
> > At any rate, canon indicates that Snape did not know the identity of the spy despite suspecting the identity of the makers of the Marauder's Map (for "men" who knew his identity and insulted him? who else could they be?), and, for the reasons given in my first paragraph, he had no reason to investigate it further.
> > 
> > Just as Harry "knew" in DH that Snape had treacherously murdered Dumbledore and wanted revenge, Snape "knew" that Sirius Black had betrayed Lily Potter to her death--and wanted revenge. <snip>
>
Steve replied:
> 
> Harry "knew" that Snape had cast the spell that resulted in DD's death because Harry saw him do it in front of his own eyes.  He didn't know that Snape had treacherously murdered DD, he assumed that.  He didn't find out til late in DH why Snape had cast that spell.  Snape did not "know" that Sirius Black had betrayed Lily Potter to her death in the same way that Harry knew Snape had AK'd DD.  Isn't Snape going on circumstantial and other kinds of evidence, not first hand observation when he believed that Sirius had betrayed Lily? There was no obvious motive for Sirius to betray people he loved and considered a 2nd family. 
> 
> Sirius's wand was never checked to see if it was the one that had cast the spell that killed all the muggles. Sirius was never questioned under veritas serum that I recall. No proof was given that I'm aware of that Sirius was the secret keeper at the time that the Potter's were killed by LV, only that Sirius was at one time their secret keeper.So, Snape didn't actually "know" for an absolute fact that Sirius had betrayed the Potters.  Snape just assumed (as did many others) that Sirius was guilty based on certain circumstantial evidence and in the absence of another suspect (Wormtail)and any actual proof to the contrary of what "apparently" happened.
> 
> Snape is the professor of a very exact science of Potion making.  Would he assume a potion was made correctly or incorrectly w/o testing it thorougly first? He wouldn't say a potion was done wrong if he didn't in fact actually know that it was done wrong.  So I don't believe Snape "knew" at all that Sirius had betrayed Lily and James.  <snip>
>
Carol responds:
I'm using "knew" (in quotation marks) as JKR (or rather, her narrator) frequently uses it, to mean what Harry (and, in this case, Snape) firmly believes to be true even though it turns out not to be. Harry also "knows" that "Moody" drinks from his own flask because he's afraid of being poisoned (that's why the real Moody drinks from his own flask, but Crouch!Moody drinks from it because it contains Polyjuice Potion). He "knows" in SS/PS that Snape is after th Philosopher's Stone. In DH, he "knows" that he'll never look into Dumbledore's eyes again. In OoP, he "knows" that Sirius Black is being tortured in the MoM. In PoA, he "knows" (just as Snape does) that Sirius Black betrayed his parents.

Now granted, Harry has more reason to believe ("know") that Snape "murdered" Dumbledore than Snape does to "know" that Black betrayed the Potters. Nevertheless, Snape's "knowledge" is not baseless. A variety of Muggles (unfortunately, now robbed of their memories of the event) testified that Black had blown up the street and killed thirteen people. Nothing was found of Pettigrew except a finger. Fudge and the Aurors believed the Muggles, who were completely fooled by Wormtail's disappearance and diversionary tactic into believing that he was dead. What else were they supposed to think? That he'd Transfigured himself into a rat? No one knew that he was an illegal Animagus. That's how he got away, literally, with murder. Snape has no reason not to believe what everyone else believes, especially given Dumbledore's testimony (which he has no reason to doubt) that Black was the Potters' Secret Keeper.

Now, granted, Snape had his own reasons for wanting to shift his own share of the responsibility for Lily Potter's death onto the betrayer of the Potters. He had, after all, asked Voldemort to spare her and Dumbledore to protect "her/them," and he's clearly devastated when those efforts fail because their Secret Keeper betrayed them. And, just as Harry finds comfort in scapegoating Snape rather than facing his share of the blame for Sirius Black's death, Snape takes comfort in blaming the hated Black, whom he truly believes tried to murder him when they were both sixteen, for his share in Lily Potter's death.

He has neither reason nor motivation to search for any other explanation. It's Sirius's supposed betrayal of Lily, not the "Prank" or SWM, that makes Snape so determined to turn in the man he thinks has been trying all year to murder Harry. (He can't possibly know that Black, who did get into Hogwarts and slash first the Fat Lady's painting and then Ron's bedcurtains, was trying to murder Ron's rat!) Not only is he too furious to listen and too determined to turn in the murderer and his werewolf accomplice to listen to "reason," the small bits of the story that he's heard are too ridiculous to believe when he himself knows the "true" story.

I do understand why some people think that *Dumbledore,* who knew Sirius Black as an Order member, should have gone to talk to Black and find out the truth. But Snape not only had no reason to investigate further, he had no means of finding out the truth. As you say, no one bothered to check Black's wand or give him Veritaserum or use Legilimency on him, so *no one* knew the truth of what had happened. No one except Sirius Black, whom Snape was not about to visit in prison and ask for the real story, and a rat named Scabbers, whom Snape had no way of knowing was an Animagus named Peter Pettigrew, believed by Snape, Dumbledore, Fudge, and everyone else in the WW to be dead.

Snape's actions and reactions in PoA, like Harry's throughout the series, are based on what he "knows" (i.e., an incomplete or inaccurate version of events that the character takes to be the whole truth). McGonagall, who taught and liked Sirius Black, also "knows" that he betrayed the Potters and killed thirteen people, just as she "knows" that Peter Pettigrew is dead. If McGonagall, who has no reason to see Black as a potential murderer or traitor, believes that he committed these crimes, why wouldn't Snape, who saw what he believes to be the murderous side of Black when they were both teenagers? Yes, he wants to believe it, but there's nothing else *to* believe since the only other person who might have killed the Muggles "died" in the explosion, with nothing left of him but a finger.

Carol, wondering just how and why Snape is supposed to investigate a seemingly open-and-shut case for which there is no evidence in favor of the accused