The New York Times has obtained harrowing new jail footage of the final hours of diabetic Rikers Island inmate Carlos Mercado, who died because correctional officers had taken away his insulin.

Mercado, 45, was arrested in August 2013 for attempting to sell a small amount of heroin to an undercover officer. He died in in jail at Rikers Island 15 hours later, as corrections officers ignored his pleas for help and his quickly worsening symptoms.

The video shows Mercado collapse face-first when officers open the cell door. Rather than check his condition, officers step over and around his prone body. Later, he weaves around the jail, vomiting repeatedly and carrying a plastic bag of his own vomit.

Internal investigations found that Mercado repeatedly asked for a doctor and told the officers he was diabetic. According to the Department of Corrections report, officers dismissed his pleas, saying he was just withdrawing from drugs.