Derrick Perry didn’t need a badge to stop evil. He just needed courage—and a gun. The Marine veteran is being hailed as a hero after stopping a stabbing rampage at a Walmart in Traverse City, Michigan, where 11 people were attacked on Saturday.

Security footage shows Perry standing in the Walmart parking lot with his firearm pointed at the attacker as other bystanders shouted, “Drop the knife!” Law enforcement confirmed Perry and others managed to disarm and detain the suspect—without firing a single shot—until deputies arrived.

Grand Traverse County Sheriff Michael Shea praised Perry and the civilians who stepped in. “It’s not very often that we have citizens that are willing to step up and take action,” he said. “What they did was amazing.”

The suspect, identified as 42-year-old Bradford James Gille of Afton, Michigan, is now facing terrorism charges and 11 counts of assault with intent to murder. He allegedly used a folding knife with a 3.5-inch blade during the attack. According to officials, Gille acted alone and there is no indication of additional suspects.

The victims, who range in age from 29 to 84, are all expected to survive. As of Monday, one patient had been released from Munson Healthcare, while others were reported in fair or good condition. One remained in serious condition, and two were treated and transferred.

Social media quickly lit up with praise for Perry’s brave actions. The Facebook group “Overheard in Traverse City” posted a tribute: “This is Derrick Perry! He is the hero from today’s stabbing at Walmart, he is the man that took his gun out and risked his own life to save many lives! Thank you so much Derrick.”

Perry’s daughter responded proudly, calling it a “proud daughter moment,” while his daughter-in-law described him simply as a “true hero.”

Even the National Association for Gun Rights weighed in, tweeting that Perry “deserves recognition” as a “good guy with a gun.”

Law enforcement is still working to determine Gille’s motive. For now, what’s clear is that the tragedy could have been far worse—if not for the decisive action of one armed Marine.

In an era where many question the role of lawful gun ownership, Derrick Perry has become living proof of how an armed citizen can stop a massacre. He didn’t wait. He didn’t hesitate. He acted—and saved lives.