Now, they're left in shock.
The 23 year old was killed Thursday when a military helicopter went down in Afghanistan.
He joined the army in 2007, after graduating from Pekin High School.
"He was ready to take, whatever the job was and go through it, do everything he could 110% and finish it out and be proud of what he did," said friend and fellow JROTC Cadet Brennan Spiesz.
Twenty three year old Spiesz went to Pekin Community High School with Shaffer, and served with him all four year in the JROTC Military Training Program.
"He was in the drill team in ROTC, and he was in the rifle team with me for a short time, and he did a lot of community service," reflects Spiesz.
The 23 year old says he always respected Shaffer.
Not only did the soldier help his hometown, Spiesz says Shaffer followed his heart to bigger missions, like protecting his country.
"It's exactly what Dean wanted to do, it takes a really brave person to be able to go into the military and do the things that he did," said Spiesz. "We don't have enough people like that."
Spiesz's memories of their time together are captured in his yearbook photos.
Looking back, he says he wishes they could have spent more time together.
"Right after high school he went into the military, I went to pursue further education. And I really wish I would have kept up with him a little bit more."
But in the end, Spiesz says he's proud of this hero, who he believes lived his life exactly the way he wanted.
Defending America's freedom on the front lines.