At a news conference on April 16, Bryan Stirling, the director of the South Carolina Department of Corrections, tried to explain why seven men had been stabbed to death and many more had been severely injured by their fellow prisoners at the Lee Correctional Institution. A fight had broken out the night before between rival gangs over “territory, contraband and cellphones,” Mr. Stirling said, and the priority now was to jam all illegal cellphones in the state’s prison system.

According to the many emails, calls and texts I have received this week from inside South Carolina’s prisons, however, this account is misleading, and to clamp down even harder on the men inside would be a terrible mistake.

Yes, it was a gang fight, prisoners tell me, but it was corrections officials who had decided to house rival gangs in the same dormitory, and it was the officials’ increasingly punitive policies that exacerbated tensions on the inside. The fact that the rioting went on for seven hours, and that so many died and were injured — 22 were taken to the hospital — was, they say, in no small part because corrections officers were AWOL.

Notably, it is contraband cellphones that make it possible for these prisoners to get their own accounts of the riot to the public, as well as to document their claim that corrections officials could have prevented the high death toll.