Dear XXXXXXXXX,
He can amend his return using form 1040X. He would report this loss on Scheduel D.
The problem you will have is if the IRS questions this, to prove that this is not a personal use property and personal loss.
You should list this loss on scheduel A, and it is limited to the amount in excess of 2 pecent of your adjusted gross income
Tax Preparer
GPHR Cert; U.S. Treasury Tax Advocacy Panel appointee