If the bullet was supersonic, there would have been a shock wave impinging on his shirt. Not all bullets leave through wounds. The design objective for most bullets is to penetrate deep enough to accomplish damage, but not to penetrate.
As for Tyler Robinson's handiness, they can ask him. The "why" doesn't really matter. I don't suppose thinking clearly was his strong suit. Most people live on a "It seemed like a good idea at the time" basis.
Turns out it was a Remington Core-Lokt soft point round that is intentionally designed to deform and expand on impact, preventing full penetration. Apparently this is a well known fact.
If the bullet was supersonic, there would have been a shock wave impinging on his shirt. Not all bullets leave through wounds. The design objective for most bullets is to penetrate deep enough to accomplish damage, but not to penetrate.
As for Tyler Robinson's handiness, they can ask him. The "why" doesn't really matter. I don't suppose thinking clearly was his strong suit. Most people live on a "It seemed like a good idea at the time" basis.
Turns out it was a Remington Core-Lokt soft point round that is intentionally designed to deform and expand on impact, preventing full penetration. Apparently this is a well known fact.