Can't answer based on no knowledge other than the sentence. You'll need to speak with an attorney that focuses on post conviction relief. I will say this though, assuming he's been in prison for a while now and he's exhausted all of his appeals, his options are extremely limited and success would be unlikely.
Your brother has a right to appellate review of all errors on the record. If he receives no relief, he may then file sate post-conviction proceedings for errors not determinable on the record, but adduced as additional evidence. Usually there are claims of ineffective assistance f counsel. He has a right to an evidentialry hearing to bring in testimony and evidence outside the record.
After exhausting state remedies, he may then start the process again with the feds.
It's a long and costly journey, even for slam dunk cases. Chances of success tend to be slim, but occasionally a person gets commuted to a term of years.
The Louisiana Appellate Project should have been appointed to raise his appeal.
DISCLAIMER: This ain't legal advice, and I ain't your lawyer. This is just idle chat regarding current events. You probably really should to go talk to a lawyer face to face.
Years licensed, work experience, educationLegal community recognition
Peer endorsements, associations, awardsLegal thought leadership
Publications, speaking engagementsDiscipline