Serena Williams speaks out against police killings in the US following Terence Crutcher murder

‘Why do I have to think about this in 2016? Have we not gone through enough?’ asks Williams

Williams says she ‘won't be silent’ on the problems of police brutality against black men in America (Adam Davy/PA)

Serena Williams has spoken out against policing killings in America, vowing she “won't be silent”.

The tennis champion posted a public message on Facebook two weeks after the fatal police shooting of 40-year-old Terence Crutcher, saying there was still “further to go” and pledging to speak out more on the issue.

She wrote: “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.

“In the distance I saw cop on the side of the road. I quickly checked to see if he was obliging by the speed limit. Then I remembered that horrible video of the woman in the car when a cop shot her boyfriend.

“All of this went through my mind in a matter of seconds. 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 realised we must stride on – for it’s not how far we have come but how much further still we have to go.

“I than wondered than have I spoken up? I had to take a look at me. What about my nephews? What if I have a son and what about my daughters? As Dr Martin Luther King said: ‘There comes a time when silence is betrayal’.”

Ms Williams ended the post with the words: “I won't be silent”, and signed it off with her name.

Her words came two weeks after Terence Crutcher was fatally shot. It is claimed he had his arms raised when the single shot was fired.

Tulsa Police Officer Betty Shelby has said she shot him in self defence when she saw him reach for something through the window of his car.

She has been charged with first-degree manslaughter.

Ms Williams’ Facebook post received more than 90 likes, 15,600 shares and 22,500 comments, mainly from people showing their support in the fight against police brutality and racism in America.

Last year the tennis star spoke out about the death of Christian Taylor, a 19-year-old college student who was shot by a police officer in Texas.

Ms Williams used Twitter to communicate the message: “Really? Are we all sleeping and this is one gigantic bad nightmare? #ChristianTaylor how many hashtags now?”

The tweet received a similarly large reaction, garnering more than 9,000 likes and almost 13,500 retweets.

Williams has shown support for the Black Lives Matter movement, which has gained momentum in the past year after a string of alleged killings by police of young black men.