Washington: A Justice Department probe has concluded that the police in Ferguson where a white policeman shot dead an unarmed black teen last August, engaged in a \"pattern and practice\" of discrimination against African-Americans.

The Ferguson Police Department and the city\'s municipal court also targeted them disproportionately for traffic stops, use of force, and jail sentences, CNN reported citing a US law enforcement official briefed on the investigation.

US Attorney General Eric Holder ordered a civil rights investigation after the police shooting that killed Michael Brown triggered weeks of protests in the predominantly black small US town.

Several stores, including some owned by Indian-Americans, were looted in the St. Louis, Missouri, suburb of 21,000 people, over two thirds of them black, but policed by 53 police officers all but three of them white.

The investigators also found evidence of racist jokes being sent around by Ferguson police and court officials.

One November 2008 email read in part that President Barack Obama wouldn\'t likely be president for long because \"what black man holds a steady job for four years.\"

Another joke that made the rounds on Ferguson government email in May 2011 said: \"An African American woman in New Orleans was admitted into the hospital for a pregnancy termination.

\"Two weeks later she received a check for $3,000. She phoned the hospital to ask who it was from. The hospital said: \'Crimestoppers\'.\"

From 2012 to 2014, 85 percent of people subject to vehicle stops by Ferguson police were African-American, CNN said citing the findings.

While 67 percent of the Ferguson population is black, as many as 90 percent of those who received citations were black; and 93 percent of people arrested were black.

In 88 percent of the cases in which the Ferguson Police reported using force, it was against African-Americans.

Black drivers were twice as likely as white drivers to be searched during traffic stops, but 26 percent less likely to be found in possession of contraband.

Blacks were disproportionately more likely to be cited for minor infractions like jaywalking and \"failure to comply\".

The findings in the investigation are expected to be made public Wednesday.

The Justice Department is likely to pursue a court-supervised consent decree that requires the city of Ferguson to make changes to its police and courts.

US probe finds racial bias against blacks in Ferguson