A 75-year-old disabled veteran has been sentenced to death due to a mandatory sentence involving marijuana possession.

Lee Carroll Brooker grew marijuana plants in his son’s backyard in Alabama for his own medical use. When Alabama officials found out, they arrested Brooker, and sent him to prison for life without the possibility for parole.

Vox.com reports:

How did this happen? Jesse Wegman explained for the New York Times:

[Brooker] said the plants were for his own medicinal use only — he suffers from multiple chronic ailments — and prosecutors did not dispute that.

Remarkably, they didn’t have to. Alabama, like three other states, mandates a life without parole sentence for simple possession of small amounts of marijuana by people with certain prior felony convictions — and Mr. Brooker had been convicted of a string of robberies twenty years earlier in Florida, crimes for which he served 10 years in prison. In such a case, the law doesn’t require prosecutors to prove any intent to sell the drug.

In Mississippi, 30 grams — barely one ounce — is enough to send someone to prison for the rest of his or her life, with no chance of release. Alabama’s cutoff is slightly higher, at one kilogram, or 2.2 pounds, but that makes no more sense, and was no help to Mr. Brooker, whose plants weighed in at 2.8 pounds, including unusable parts like stalks and leaves.

So Brooker, an elderly man with disabilities, is now serving a life sentence for a string of robberies 20 years ago, for which he already served time, and marijuana possession.

It’s an incredible situation, not least because Brooker likely wouldn’t be in prison if he lived in one of the 24 states that allow people to use pot for medical purposes or four states that let people use the drug for any other reason.

Brooker’s situation is very rare — a minority of prisoners are in for drug offenses. But Brooker’s story shows how out of step drug laws can be with public opinion, especially since a majority of Americans agree marijuana should be legal. Even Alabama Chief Justice Roy Moore, who’s notoriously conservative, called Brooker’s sentence “excessive and unjustified.” (The sentence was mandatory — so once prosecutors brought charges that triggered the sentence, judges were required to enforce it.)

There’s also research that suggests these tough sentences don’t deter drug trafficking. A 2014 study from Peter Reuter at the University of Maryland and Harold Pollack at the University of Chicago found there’s no good evidence that tougher punishments do a better job of reducing drug use and substance abuse than lighter penalties.

As extreme as the penalty may seem, the US Supreme Court earlier this week declined to hear a challenge to Brooker’s sentence. He had appealed his case, arguing that such a harsh punishment for marijuana violated his Eighth Amendment protections against cruel and unusual punishment. With the Supreme Court’s refusal to hear the case, the sentence remains legal for now.