Police officers, security guards, or self-appointed vigilantes extrajudicially killed at least 313 African-Americans in 2012, according to a recent study. This means a black person was killed by a security officer every 28 hours. The report notes that it's possible that the real number could be much higher.

The report, entitled "Operation Ghetto Storm," was conducted by the Malcolm X Grassroots Movement, an antiracist grassroots activist organization. The organization has chapters in Atlanta, Detroit, Fort Worth-Dallas, Jackson, New Orleans, New York City, Oakland, and Washington, D.C. It has a history of organizing campaigns against police brutality and state repression in black and brown communities. Their study's sources included police and media reports along with other publicly available information. Last year, the organization published a similar study showing that a black person is killed by security forces every 36 hours. However, this study did not tell the whole story, as it only looked at shootings from January to June 2012. Their latest study is an update of this.

The report (pdf) can be read at the link.