Death row
A US death chamber where executions by lethal injections are carried out. Richard Glossip is set to be executed next Wednesday Getty

Richard Glossip is set to be executed by Oklahoma on Wednesday, 16 September. But he is thought to be innocent by many and insists he is being killed for a crime he did not commit.

Glossip was convicted of ordering in the murder of his boss, hotel owner Barry Van Treese, on the sole testimony of the actual murderer. Although Glossip did not take part in the murder, Justin Sneed, the handyman at the hotel who killed Van Treese implicated him, in return for not being given the death sentence for the crime.

Glossip has maintained his innocence from the very beginning. He was twice offered a life sentence twice in exchange for an admission of guilt, but he refused both times. He told The Intercept, hours after his execution date was set, "I'm trying to stop them from killing me by any method, because of the fact that I'm innocent."

Campaigners including Susan Sarandon and Sister Helen Prejean, who Sarandon portrayed in the biopic Dead Man Walking, are still fighting to save Glossip's life. Sarandon has written that Glossip finds himself on death row on one man's dubious testimony for his alleged role in the murder of Van Treese.

Sneed's testimony and new evidence

Justin Sneed told police that on the morning of 6 January 1997 he beat Van Treese to death. He claimed his boss, Glossip, ordered the then 19-year-old to do it. There was, however, no physical evidence corroborating Sneed's accusation.

Glossip's attorneys have come up with new evidence they never presented until now – the first red flag being how police interrogated Sneed – the Mirror reports that in the first three times Sneed recounted the murder to authorities, he didn't even mention Glossip's name. "The only thing that ties Richard Glossip to this case are the words of Justin Sneed," said Glossip's lawyer Don Knight.

But Oklahoma Governor Mary Fallin, of the Republican Party, is not wavering in her decision not to grant a stay of execution. This is in spite of new evidence being brought in by Glossip's defense team.

Controversy over drugs

Glossip's name became synonymous with the legal fight over midazolam. The drug has been linked to a number of botched executions, including one in which a prisoner took 45 minutes to die, drawing international condemnation. Despite this, the US Supreme Court ruled the use of the drug for lethal injection executions is constitutional in July 2015, because prisoners have the option of being killed using alternative methods.