"Today, I asked my 18-year-old nephew (to be clear, he's black) to drive me to my meetings so I can work on my phone #safetyfirst," she wrote. "In the distance I saw a cop on the side of the road."
Williams explained that after checking to make sure her nephew was obeying the speed limit, she began thinking about Lavish Reynolds, who posted a video in July of herself in a car beside her dying boyfriend, Philando Castile, after she says police shot him four to five times.
"All this went through my mind in a matter of seconds," Williams continued. "I even regretted not driving myself. I would never forgive myself if something happened to my nephew. He's so innocent. So were all 'the others.'
"I am a total believer that not 'everyone' is bad. It is just the ones that are ignorant, afraid, uneducated, and insensitive that is affecting millions and millions of lives.
"Why did I have to think about this in 2016? Have we not gone through enough, opened so many doors, impacted billions of lives? But I realized we must stride on- for it's not how far we have come but how much further still we have to go.
Meanwhile, many athletes have been kneeling during the national anthem before competitions in protest of police brutality. The trend began after San Francisco 49ers quarterback Colin Kaepernick began his silent protest during the NFL's preseason.
Earlier this month, Kaepernick vowed to donate the first $1 million he earns this season to community organizations to further help his cause.