A year and a half ago, a news story exploded out of Sanford, Fla. George Zimmerman, an armed, 28-year-old man of mixed white and Hispanic ancestry, followed and killed Trayvon Martin, an unarmed 17-year-old African American. The tragic episode was touched off because Zimmerman, out on neighborhood watch patrol, found Martin to be suspicious as he walked home from a store wearing a sweat shirt with a hood.

As the days and months unfolded and more details emerged, the national media ran with the story, and along the way something became quite apparent to me. As captivating as this story was, with controversial elements touching on a range of issues from vigilantism to gun control, the component of race kept the conversation largely private. It was a story that you could only fully expound upon in rooms where everyone looked like you.

Last month, when a jury found Zimmerman not guilty in Martin’s death, it wasn’t the end of the story. People young and old, black and white, took to the streets from coast to coast. For Zimmerman, too, much was not resolved; whatever you may think of him, he can’t be happy that he killed a young man on the cusp of adulthood, with dreams and goals and loving parents who presented the most graceful bearing of grief I’ve ever seen.

I needed to do something. The Monday after the trial ended, I went to my job at a small doctor’s office and made my computer desktop wallpaper (which was not viewable to the public) an image of a hoodie. This image had sprung up on the Internet and social media as an expression of support for the Martin family. It is meant as an acknowledgement that this senseless death had not gone unnoticed.

Then, at the end of the week, President Obama went into the White House press room and made history. He said that Martin could have been him. As the only president we’ve had who could say such a thing, Obama conveyed his experience being a person of color and told the world that his story wasn’t unique. Our president asked that we “do some soul-searching.” He let us know that he didn’t have much faith in politicians organizing conversations on race, but he said that he thought that in our families, churches and workplaces we might succeed.

But that’s not what happened in my case. On Aug. 1, at the end of a long work day, my boss called me into his office. Apparently, during the two weeks since I had selected the hoodie image for my computer desktop, some of my co-workers had complained. They felt that this image, which could be seen only when I logged in or minimized all the windows open on my screen, was inappropriate. My boss, looking distressed, told me that I had to change it.

There was no room for discussion between him and me or me and them. There would be no way to explain, to anyone who felt frightened or threatened by what I had done, that I wasn’t making some call to arms, or a black-power salute, or in fact trying to express any anger at all. It was merely an image of a piece of clothing worn by a young man who was wrongfully killed. By displaying it, I was simply saying that I was sad.

Despite Obama’s request that we work to advance the conversation on race, I’m sorry to say that I was complicit that day in halting our progress on this task. An opportunity that should have been a prelude to a real discussion on the symbolism of the hoodie or the anxiety it provoked was lost.

That’s because I left the short meeting with my boss knowing that I couldn’t take the image down. I knew that he had every right to ask me to take it down, but I would not have respected myself if I had.

I didn’t know Trayvon Martin, but his story touched me. What made me feel sad about his death was not going to dissipate with the removal of an image from my computer screen. And although the anxieties of my co-workers might be assuaged with its removal, I knew, too, that the silence that would be sure to follow would be misconstrued as progress. I wasn’t comfortable with that.

So, I went to my computer and composed a letter of resignation. It would be the last document I would ever complete at my workplace of six years. It wasn’t easy, but it also wasn’t hard. Either way, the real problem remained. When everything was said and done, the life of a young man who should have made it home safely that night still had been cut short.