With his left hand, Staff Sergeant Leroy A. Petry painstakingly printed each letter of his name. His mouth opened slightly as he focused.

“If you join the military, go Ranger,” he said to the little boy as he finished the autograph and slides the card across the table. Beaming, the boy thanked him and shook his hand.

His right hand. The robotic hand.

For the first 28 years of his life, Leroy Petry had a human right hand. There were metacarpals and articular cartilage, ligaments and muscles that enabled him to throw baseballs and write notes. He joined the Army Rangers after graduating from high school, and he learned to use his right hand to throw grenades and shoot guns.

While stationed in Paktia Province, Afghanistan in May 26, 2008, Petry woke up with his right hand in full working order and an assignment: his team was to capture a Taliban target.

The mission took them into a courtyard that contained high-value combatants. Enemy fighters engaged Petry and another Ranger as they moved through the courtyard, strafing them with automatic weapons. Both soldiers were wounded.

A bullet passed through both of Petry’s thighs, but he managed to lead his comrade to cover. With his right hand, he tossed a grenade at the enemy, providing cover for a third Ranger to join them.

The enemy responded quickly. One grenade, which injured both of Petry’s teammates, exploded nearby. Another grenade landed a few feet from him.

With a ticking bomb just a few feet away, Petry neither dove away nor ducked for cover. Thinking of his fellow Rangers, he reached out, grabbed the grenade with his right hand, and threw it.

As it left his fingertips, the grenade exploded.

Looking back, he says he doesn’t remember the pain when his right hand was severed at the wrist. At least, that’s what he said to the room full of students at Sacred Heart Cathedral School during a school visit. He said the adrenaline kicked in, and he tied a tourniquet around what was left before coordinating support for himself and the two fellow Rangers whose lives he’d just saved.

He received the Medal of Honor for his actions that day, and a robotic prosthetic hand has replaced the one he lost. He can shake hands with dignitaries and chop vegetables for dinner; his golf game, he laughed, still needs work.

Signing autographs in the downtown Holiday Inn during last week’s Medal of Honor Convention, Petry also demonstrated the abilities of his left hand. After the injury, as his then five year-old son learned how to write for the first time, Petry learned how to write for the second time, using his left instead of his right.

“We basically learned our ABCs together,” he laughed.

Despite developing Carpal Tunnel syndrome in his left wrist shortly after returning stateside, Petry re-entered the service for three more years before retiring in July. He said he’s happy to spend more time with his wife and kids.

Now he has time for events like the Medal of Honor Convention and people like Lee Wallace, a pastor at First Church of God and an avid stamp collector. Wallace came to the signing to get his Medal of Honor stamps autographed, and as the little boy walked away with his autograph, Wallace arrived at Petry’s station, waiting for his.

“It’s an honor to meet someone who’s done so much for our country,” Wallace said.

Petry touched his pen to the paper, beginning the painstaking process all over again. Above his name, he wrote “RLTW,” which he explained stood for “Rangers lead the way.”

His life and sacrifice could not make his message any clearer.