O.J. Simpson in Clark County District Court, May 17, 2013, Las Vegas
Steve Marcus-Pool/Getty Images

O.J. Simpson is asking President Barack Obama for clemency, saying he may have brain cancer and should be allowed to leave his Nevada jail cell, the Washington Times reports.

Simpson, 66, reportedly wrote a letter appealing to Obama for relief from his 33-year sentence for kidnapping and robbery, the Times says. Citing the Mirror News, the Times reports that Simpson is being tested for a tumor on his brain to determine whether he has cancer. The report says Simpson is convinced that he is will die soon.

Simpson’s health has been deteriorating for years since his imprisonment, the Times reports. He’s gained weight, suffers from blurred vision, diabetes, stuttering and failing hearing. At one point, doctors warned him to avoid sweets or else his diabetes would cause more health problems, the Times reports.

Read more at the Washington Times.