Why didn't Umbridge use legilimency against Harry?

Question

In the Order of the Phoenix, we see Dumbledore wants Harry to take extra lessons to learn Occlumency as a counter to Voldemort invading his mind, indicating that it is not something taught regularly to students his age at Hogwarts, and it seems that Harry's private lessons with Snape seem to be sort of secret

From what Snape says during the class, it probably is a breach of privacy to use legilimency on people, but it doesn't seem to be something out-right illegal such as the unforgivable curses, or highly regulated such as veritaserum

We also know from later scenes in that book that Umbridge is willing to take any steps to put Harry in his place and get information out of him (ready to use the Cruciatus curse on him in the later chapters)

If this is the case, why didn't Umbridge use legilimency against Harry during the scene when she was trying to find out where Sirius was, instead of using veritaserum? The veritaserum method ended up not working anyway, and I think from the later chapters it is revealed that it was in fact, fake.

Is there any plausible reason for why Umbridge did not use legilimency with Harry to find out the whereabouts of Sirius?

Answer 1

She had no reason to use Legilimency.

It's true that the Veritaserum she uses on Harry is fake.

"It was [Snape], too, who gave Professor Umbridge fake Veritaserum when she was attempting to force you to tell her Sirius's whereabouts."
_{(Order of the Phoenix, Chapter 37, The Lost Prophecy).}

However, at the time Umbridge (obviously) didn't know that the Veritaserum was fake. She trusted Snape right up until the point where he denied her further quantities of Veritaserum after she used the whole batch on questioning Harry.

If she believed that the Veritaserum was legitimate then she must have believed that the answers Harry was giving her were legitimate. Veritaserum is described as pretty much the most powerful truth serum there is so there would be no way for Harry to mislead her or lie to her, in Umbridge's mind at least.

Given that she believed she had access to a potion that forces the drinker to tell the truth, why would she use Legilimency? It wouldn't be able to tell her anything more than the Veritaserum could. The only advantage Legilimency has over Veritaserum is that it has no known laws governing its use, whereas Umbridge's use of Veritaserum was (probably) illegal.

"It is Veritaserum - a Truth Potion so powerful that three drops would have you spilling your innermost secrets for this entire class to hear," said Snape viciously. "Now, the use of this Potion is controlled by very strict Ministry guidelines."
_{(Goblet of Fire, Chapter 27, Padfoot Returns).}

However, by this point in the story Umbridge's desire to question Harry has become so pronounced that breaking the law was of no concern to her.

"The Cruciatus Curse ought to loosen your tongue," said Umbridge quietly.
"No!" shrieked Hermione. "Professor Umbridge - it's illegal."
But Umbridge took no notice. There was a nasty, eager, excited look on her face that Harry had never seen before. She raised her wand.
"The Minister wouldn't want you to break the law, Professor Umbridge!" cried Hermione.
"What Cornelius doesn't know won't hurt him," said Umbridge...
_{(Order of the Phoenix, Chapter 32, Out of the Fire).}

Besides, as others have said, Umbridge was hardly the world's most talented witch. It's doubtful whether she'd be able to pull off a complex branch of magic like Legilimency.

Answer 2

As we have no direct answer from the book, I suggest the following:

Umbridge is lousy at Legilimency (or, at least, is not that good)

If she were an apt Legilimens, she could use it. Otherwise, she falls back to Veritaserum, which is known to be 100% working. With Legilimency, there always is a possibility that the subject will put up a fight with Occlumency, as Harry did with Snape, or he could conceal his mind completely, as Snape did with Voldemort.

edit: As it is pointed out in a comment below, Veritaserum is also not 100% reliable (my answer was based on a false impression from books/movies only) but it is very unlikely that a teenage boy would know how to resist Veritaserum.

Also a concern - using Legilimency against an underage wizard is possibly illegal. However, Umbridge was so desperate she decided to use Veritaserum anyway.

Answer 3

As you describe, occlumency is not normally taught at Hogwarts. At the same time, though: Neither is legilimency. Considering there is no such thing as magical university, this is a type of magic people need to actively seek out and learn for themselves. We know Umbridge attended Hogwarts, so she would have been bound by this restriction.

Umbridge was also at her core a bureaucrat, and really had no good reason to try and learn legilimency. Even most aurors don't seem to bother, although it would work far more directly in their favor.

Combining these facts, the most likely reason she didn't, is because she can't.