WOW, the tax liability for anyone claiming to be Cooper was calculated for the FBI by the IRS and it is MASSIVE..
about $176,000 in 1976 plus interest every year after..
Was this an attempt to keep Cooper quiet?
I don't know if this is necessarily true.
You are liable for income tax in a calendar for three years after the due date of the tax or three years after the date you file WHICHEVER IS LATER.
So, if Cooper filed an income tax return for the 1971 tax year, but failed to report the hijacking proceeds as income, that tax year can no longer be reviewed.
On the other hand, if he never filed income tax for 1971, the three year clock has not yet started and he is still on the hook.