Darren Wilson, the white police officer who shot dead unarmed black teenager Michael Brown in Ferguson, has resigned from the police force fearing escalation of violence if he continues.
Ever since the shooting on 9 August, the police officer has been on administrative leave alongside snowballing protests against him.
Wilson, in a telephone interview with the St Louis Post-Dispatch, said he was waiting for the grand jury's verdict before officially stepping down. The Missouri grand jury had decided not to indict Wilson five days ago.
Both the shooting incident and the grand jury's verdict had triggered a series of protests in Ferguson and across the US.
"I'm resigning of my own free will. I'm not willing to let someone else get hurt because of me," said the 28-year-old officer, who has been with the police department for six years.
His lawyer Neil Bruntrager has also confirmed the resignation, which some say was expected.
Ferguson authorities are yet to formally acknowledge that he has stepped down.
In his parting letter, Wilson wrote: "I have been told that my continued employment may put the residents and police officers of the City of Ferguson at risk, which is a circumstance that I cannot allow."
"For obvious reasons, I wanted to wait until the grand jury made their decision before I officially made my decision to resign. It was my hope to continue in police work, but the safety of other police officers and the community are of paramount importance to me. It is my hope that my resignation will allow the community to heal."
Wilson added he has not discussed the severance package with the police department as yet and is hopeful of receiving it.