Rights and Responsibilities of POA?

My father is now in year two of a 25 year sentence in prison. I am his daughter and legal POA. He was a teacher and has a pension and also some retirement and non retirement investments. My question is, since he has agreed and said it was OK, can I or do I have the legal right to collect his pension? I got a letter about a month ago stating that because it's been two years since he's been out of the union, that "he" could collect on it, if he wanted too. We've already gone through an ordeal with his home and it being a VA loan and just can't jump through anymore hurdles, but if we don't collect that pension according to the DA that prosecuted my dad, it will "disappear".

Because he's 55 and doing a 25 year sentence, he's obviously going to be way older then the national legal/Oregon retirement age. What do I need to do, especially because of course they don't want to have to pay it out, but legally had to send the letter about collecting the pension.