Trust deed investment - when can I claim a loss?

[JT Marlin]

I invested in several trust deeds back in the 2005 -2006 time frame. Unfortunately, several of the trust deeds were ultimately foreclosed on. However, there is one trust deed loan that hasn't performed in years, but the investors that made up the beneficiary LLC can not agree on whether or not to foreclose - there is some concern about inheriting liability on the unfinished project (primarily taxes).

My question is, for tax purposes, when can I recognize the loss associated with that trust deed investment? The loan was made at least 5 years ago and has been non-performing for at least 4 years. Does the trust deed have to be transferred or sold before I can claim a loss?

Elsewhere, I have some capital gains that I'd like to recognize if I can offset them with losses from the aforementioned TD. Can I declare the TD substantially worthless for a particular tax year, than if the TD is ever sold, recognize those proceeds as capital gains?

I know this is a convoluted question. I hope I was able to articulate the scenario in a fashion that made sense. I also recognize that I should consult my CPA (and I will). I'd like to get some thoughts from the BP collective as well though as my CPA is very conservative.