Nearly 15 years ago, the brutal murder of three Arkansas Cub Scouts in an alleged satanic rite sickened a nation and strengthened the hand of death penalty champions across the United States. Now the same ghastly crime may be the final nail in the coffin of capital punishment in an America that is manifesting a crisis of conscience over the morality of executions.

Supporters of the “West Memphis Three” say prosecutors and a small-town police force railroaded the young men because of their fascination with heavy metal music and the occult. And they say new DNA tests and other forensic evidence call their guilt into question.

Campaigners across the US and around the world have been meeting to publicise the case of three men they believe have been wrongly convicted of a horrific triple murder.