I hadn't thought about him in a while, but  his iconic image was on the cover of what looked like a new book.  The hood of a sweatshirt is pulled over his head. His big eyes look  soulful.

Trayvon Martin.

The Florida teenager's 2012 death sparked the rise of the Black Lives Matter movement. Almost five years later,  he's still an international symbol of the ills of the U.S. criminal justice system.  I picked the book up.

Rest in Power: The Enduring Life of Trayvon Martin was written by Martin's parents,  Sybrina Fulton and Tracy Martin.  It was just lying on a shelf for the taking. I scooped it up. A few days later, I was chatting on the phone with  Trayvon's parents about their son, Emmett Till, and the couple's surprising ambition to run for political office.

"We opened the eyes of America by not just settling for this case as an open-and-shut case," said Martin. "We shed a lot of light on the injustices that were happening to our young men and women across the country. ... From the birth of the Trayvon Martin incident came Black Lives Matter."

Trayvon's parents are scheduled to sign copies of their book at the Central Library of the Free Library of Philadelphia at 7:30 p.m. Thursday.

George Zimmerman, a volunteer neighborhood watchman, was  acquitted of second-degree murder in the death of Trayvon, who was unarmed and walking from a Florida convenience store when confronted. The case sparked widespread demonstrations and debate about race relations, even prompting then-President Barack Obama to weigh in on the issue.

Seemingly overnight, Trayvon's parents were pushed into the spotlight. Martin, then a truck driver,  and Fulton,  a civil servant, became regulars on TV news programs and at demonstrations.  I often watched them, wondering how they did it.  I never once saw them cry or lose their cool. They were always stoic but insistent that a miscarriage of justice had occurred.  Even though they were divorced, they were a united force when it came to their son, great role models for people everywhere.  All these years later, they're still crusading and also toying with political careers.

"That's something that we are just researching and we are considering, because we want to be a part of the change," Fulton told me.  "We are just taking a look at it."

Rest in Power  walks readers through the tragically short life of Trayvon. His parents admit that he was a typical teenager and far from perfect.

"A lot of times, people try to justify why he was killed and they come up with all kind of things -- 'Oh, he was a thug. He was suspended from school' -- but that does not justify somebody shooting and killing someone," Fulton said.

At one point during our conversation, Till's name came up. He was a 14-year-old black boy savagely beaten in Mississippi in 1955 after he allegedly whistled at a white woman.  The case was notorious, especially after his alleged killers were acquitted by an all-white jury. Over the weekend,  America got the gut-wrenching news that Till's accuser, Carolyn Bryant Donham, had finally admitted to lying - something black America had been convinced of all along. Martin sees parallels between what happened with Emmett Till and Trayvon.

"That speaks to how we have preconceived notions about young African American boys and girls in society," he said.  "The reason that that's so big to us is, we think that the killer of our son - not knowing who he was - prejudged who he was and prejudged his character, and it ended up with the death of our son."

Because of that, Trayvon's name, along with Till's, is now a footnote in black history.