James Broadnax has been locked up in a 6ft-by-10ft cell on death row in Texas for more than 16 years, and in that time he has developed coping mechanisms for passing the long and desolate days.

A favourite technique is to write spoken word poetry at his cell desk. He becomes so engrossed in the creative process that he can lose himself for hours, transfixed in what he calls a “time gap”.

Broadnax is set to enter the execution chamber in Huntsville, Texas, on 30 April. He will be strapped to a gurney and injected with a lethal dose of pentobarbital – his life snuffed out in no small part because of the prosecutorial use, or misuse, of his poetry. In 2009, Broadnax, who is African American, was convicted along with his cousin of murdering two white men, Matthew Butler and Stephen Swan, during a robbery in Garland, Texas. He was found guilty by a jury from which Dallas county prosecutors had initially excluded all Black jurors, until the trial judge stepped in and reinstated one of them.

During the sentencing phase of Broadnax’s capital trial, prosecutors presented the jury with 40 pages of the defendant’s notebooks found in a suitcase after his arrest. The state carefully selected rap lyrics infused with violent images of murder, robbery and drugs, to make the case that Broadnax should be sentenced to death. Its lawyers skirted over lyrics addressing peaceful narratives such as redemption and love. For the ultimate punishment to be secured under Texas law, jurors would have to be persuaded that the defendant posed a threat of “future dangerousness”.

By leaning heavily on rap lyrics and racist dog whistles, Texas prosecutors managed to drown out mitigating evidence that might have spared Broadnax’s life. His defense lawyers emphasised that Broadnax was just 19 when the murders took place. He had endured an abusive childhood at the hands of a grandmother who locked him up in his room without food and frequently beat him. And despite such a traumatic background, he had no previous criminal record other than a single conviction for non-violent marijuana possession.

The jury was clearly less swayed by such details than by the prosecutors’ lurid invocation of the rap lyrics. Jurors asked to see the notebooks twice during their deliberations. Then they sent Broadnax to death row.