This way they could tuck him away for a couple of years until his father got his mind back and was fit to take care of him. Not that Henry’s father had ever been good for anything anyhow.

Henry wouldn’t look at me in the courtroom. I hadn't seen him since the night the paramedics took him away. Half of his head was still covered in bandages. Even as I spoke the words that condemned him, all I could think was that Henry would never look at me again.

“I testified against my best friend in front of the entire court room. Not that it made any difference, everyone already believed me. They wanted to believe me. They needed to believe me. If they hadn’t, where else would Henry Dietrich go? “

Minor nits: The “entire courtroom” and “everyone” seem a bit vague, in terms of people and setting. Did the proceedings involve a jury? It sounds like it was open to the public, which may allow for raising the ante of who was there. Also something sounds off in matching the verb tenses in that last sentence, but I can’t pinpoint it.

“This way they could tuck him away for a couple of years until his father got his mind back and was fit to take care of him. Not that Henry’s father had ever been good for anything anyhow. “

Main nit: This paragraph pulled me out: It sounds like Henry is a madman being put into an insane asylum, but his father isn’t mentally stable either; how does anyone know the father will be better in two years? Is it important to know, right now, that the father is good-for-nothing?
I do like the idea of safely tucking him away… is that for his sake or the public’s? (I suspect his, but it’s not entirely clear because you just spoke about how badly the people needed to believe your MC.)

“Henry wouldn’t look at me in the courtroom. I hadn't seen him since the night the paramedics took him away. Half of his head was still covered in bandages. Even as I spoke the words that condemned him, all I could think was that Henry would never look at me again. “

Minor nit: courtroom again; we know that’s the setting. Is he in the stand? Behind his lawyer? Otherwise I liked the tension.

“I wouldn’t look at him either. How could I? We both knew I was lying.”

Great hook!

I hope you will soon establish ages, because at this point I have no idea. My guess is maybe teens?

I thought that paragraph was the main hook for me. The question of how someone would know that the father would be better in a couple years seems to be integral to the backstory. I trust that it will get explained, and as such there is no need to extrapolate within the first 13. The hint that the father is good for nothing adds another degree of mystery: Whats the history between the MC and Henry? If they were friends why is the MC lying now?

I do agree with some of the nitpicks, about the word tense seeming off, and I definitely played around with it for a while.

It's hooooookie as all get out. But I would change the "all I could think was that Henry would never..." to a dirct pharse like "Henry wouldn't look at me." It's 1st person POV so we know it's a thought.