The defendant was found guilty of burglary and sent to prison.

I prefer the first.

Why not 2 and 3?

You asked for a preference. I gave you mine.

Got it. Did you find something wrong with the last two ones as well?

No, they are both possible. In my experience, the first is most common.

In the American court system a jury "finds" you guilty or not guilty. The judge doesn't arbitrarily "declare" you guilty.

"You have been found guilty by a jury of your peers" is how it goes.

Not all trials are jury trials. Judges can "pronounce" and "declare".

Even in a judge trial, he or she "finds."

Yes, but the others are also possible.

I am not a teacher.

In England, if the defendant is not declared unfit to stand trial and is found guilty, the judge will pronounce sentence.

Judges do and say a lot of things.