The Game

Tom Block hopes one day the Captain America shield in his eye will be a sign a child is safe

Largo, Florida (CNN)Ret. Sgt. Tom Block is sitting in the classroom, looking restless. He and 23 other highly specialized, highly coveted candidates are all vying for a job where they will be exposed to some of the most horrifying images humanity can produce.

Each candidate is a veteran of America's recent wars. Many were part of the elite special ops forces. They conducted daring, covert missions to take out America's most dangerous enemies.

Many were wounded in battles across Afghanistan and Iraq. And now that their military career has come to a close, they are looking for a second chance to find purpose in their lives back at home -- and the answer could be the HERO Child-Rescue Corps, saving at risk kids.

J. Christian, CEO of the National Association to Protect Children (Protect), says: "A lot of the individuals who come into the HERO Corps are truly individuals who have lost their mission on the battlefield."

Christian, an Army Ranger who fractured his spine during a mission in Afghanistan, says many of the veterans who come into HERO are hoping to regain that something they lost when they left the service.

Block is hoping to get a second chance to "go after bad guys again."

"In one second their entire life changed. When that happens, I know from personal experience, you start to wonder, what can I now do? And once you find this opportunity, you know it's truly your opportunity to step back into that role."

The HERO -- Human Exploitation Rescue Operative -- program is designed for wounded, injured and ill veterans to receive training in sophisticated computer forensics, to join federal agents fighting against online child sexual exploitation.

Developed by Protect, in conjunction with Homeland Security Investigations (HSI) and U.S. Special Operations Command (SOCOM), the veterans receive 11 weeks of intensive training and 10 months of on-the-ground experience.

They work alongside law enforcement teams executing warrants and serving as computer forensic analysts as part of a year-long unpaid internship. That means scanning computers and external hard drives on-site to determine whether the suspect possesses child pornography and, critically, whether the suspect is also producing child pornography.

During that year-long internship, HERO Corps trainees will sift through thousands of disturbing images of adults sexually assaulting children.

"You see groups of children being abused at levels the average American cannot fathom. If you imagine an infant getting gagged and bound and tortured, it's not a rare occurrence to come across," says Christian.