Suppose you spent five years in prison for a crime you didn't commit. How much does the government owe you?

Over the past few decades, the rise of DNA exonerations has made this a more pressing question. And many states have created explicit policies to answer it.

But those policies vary wildly from state to state.

Twenty-one states provide no money — though people who are exonerated can sue for damages. Twelve states and the District of Columbia award damages on a case-by-case basis. Another 17 states pay a fixed amount per year of imprisonment.

And among states that pay a fixed amount per year, there's a huge range of payments.

Several states and the federal government offer $50,000 per year for people wrongly convicted in federal court. Why is that such a common figure?

Federal payments were set by a law passed a decade ago. At that time, Alabama had the highest compensation at $50,000 per year, so the feds simply decided to match that, according to Stephen Saloom, policy director at the Innocence Project. Other states may have followed the lead of the federal government.

"There doesn't seem to be any other rationale behind the number," said Paul Cates, also at the Innocence Project.

One other interesting idea: States that pay the wrongfully convicted might actually be trying to save money, according to Brandon Garrett, University of Virginia law professor and author of Convicting the Innocent.

That's because people who are exonerated can sue states — and sometimes win awards on the order of $1 million per year of imprisonment, Garrett says.

In many states, people who are exonerated have to give up their right to sue in order to collect the set payment.

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