A surveillance video taken at an Ohio prison shows a brutal knife attack targeting four black prisoners who were shackled to a table.

The Associated Press obtained surveillance video of a white prisoner attacking a group of inmates who were handcuffed to the table in a recreation area at the Southern Ohio Correctional Facility in Lucasville while playing cards. The graphic video, taken in June 2017, shows the attacker stab and severely injure the prisoners as the inmates tried to free themselves from the handcuffs. As the Associated Press report notes, it took nearly a minute for any prison guards to respond to the violent attack, though by that point one of the victims had freed himself and fought back against the attacker, identified as Greg Reinke, who had reportedly smuggled two knives into the recreation area.

WARNING: GRAPHIC VIDEO

Shamieke Pugh, who was suffered multiple stab wounds and has since been released from prison, told the Associated Press that he felt Reinke intended for the attack to be fatal.

“He was trying to kill us, for sure,” Pugh told the news outlet, adding that he thinks the attack was set up by prison guards.

Prison officials, the prison guard’s union, and the prosecutor who filed charges against Reinke have reportedly all said they do not believe the attack was planned by prison guards. The prosecutor also reportedly told the Associated Press that he has not found evidence the stabbing was racially motivated.

A prison report obtained by the news outlet stated that Reinke said “he just felt like killing someone” in regard to the June 2017 stabbing.

Reinke, who was already serving a life sentence on murder charges, reportedly stabbed a prison guard multiple times just seven months after the first attack — injuring the guard so severely that he had not been able to return to work in nearly a year.

According to the Associated Press report, the prison guards’ union has since discontinued the practice of handcuffing inmates seated at tables.