@LRHRN Credit where credit is due, he sounds like a reformed character, despite the minimising of his past. But sadly I think his past maybe his undoing where the US is concerned and to be honest, who in their right mind would want to move to the US right now?
It doesn’t matter that the convictions are pre‑2004 or “spent” under UK law, the US doesn’t recognise the British concept of spent convictions at all. They look at the type of offences and the number, not how long ago they happened or whether someone has turned their life around.
Assault, battery, theft and false imprisonment are all classed as serious offences under US immigration rules, and multiple convictions (even decades old) usually mean the person is inadmissible. They class it as moral turpitude.
This is a good place to look at their standards. www.uscis.gov/policy-manual/volume-8-part-d?utm_source=copilot.com
The US system is very black‑and‑white about this. Rehabilitation is lovely and important in real life, but unfortunately it doesn’t carry much weight with US border officials.
Have you been on holiday to the states because I don't think he would be able to use ESTA. It’s the online form people from visa‑waiver countries (like the UK) fill in to visit the US for up to 90 days. It asks questions like, have you ever been arrested, have you ever been convicted of a crime involving moral turpitude, have you ever violated any law relating to controlled substances? If you answer yes to any of these, you are not eligible for ESTA and must apply for a full visa instead. From what you have said, had he answered truthfully, it would have been yes and he would have needed to apply for a full VISA, and they will see the entire history. With several violent/property offences, a tourist visa is still very likely to be refused. So has he been to the States, because if so, did he lie on the ESTA?
For moving to the US, the bar is even higher. Multiple convictions for violence and theft, even from 20+ years ago, almost always mean no green card, no long‑term visa, no waiver.
So yes, he may be a reformed character now, but sadly the US system doesn’t take that into account. The age of the convictions doesn’t fix the problem.
Sorry OP, I migt be wrong, but I don't think I am.