Hawkins wore the black shirt during pre-game warmups and introductions Sunday before Cleveland hosted the Cincinnati Bengals. The messages read: "Justice for Tamir Rice and John Crawford" on the front and "The Real Battle for Ohio" on the back.
The 12-year-old Rice died Nov. 22 after he was shot by a rookie officer investigating a complaint about the youngster, who was carrying a fake gun. Crawford, 22, was fatally shot Aug. 5 while holding an air-pellet rifle inside a Walmart in Beavercreek, Ohio.
"I have a two-year-old little boy, that same two-year-old little boy everyone says was cute when I jokingly threw him out of the house earlier this year," Hawkins said. "That little boy is my entire world and the number one reason for me wearing the T-shirt was the thought of what happened to Tamir Rice happening to my little Austin scares the living hell out of me."
Hawkins spoke for six minutes Monday at his locker. He did not take any questions and said he wanted to address the situation after Cleveland police union president Jeff Follmer called his actions "pathetic" and told cleveland.com that Hawkins is "disrespecting the police on a job that we had to do and make a split-second decision."
The Browns say they respect the police and their player's rights to protest.
Hawkins said he was "scared" of a backlash, but chose to wear the shirt "because deep down I felt like it was the right thing to do."
"I utterly respect and appreciate every police office that protects and serves all of us with honesty, integrity and the right way," he said. "And I don't think those kind of officers should be offended by what I did."
Hawkins said his mother raised him to respect law enforcement and he has family and close friends who are police officers. She also taught him to stand up for his beliefs.
"My heart was broken for the parents of Tamir and John Crawford, knowing they had to live that nightmare of a reality," he said. "I made the conscious decision to wear the T-shirt. I felt like my heart was in the right place, I'm at peace with it and those who disagree with me, this is America. That's the point. Everyone has a right to their First Amendment rights."
AP NFL websites: http://www.pro32.ap.org and http://www.twitter.com/AP_NFL