Federal prosecutors declined to pursue civil rights allegations against law enforcement officers 96 percent of the time since 1995, a newspaper found, with most experts blaming the low prosecution rate on the difficulty of winning such cases.

According to a report released by the Pittsburgh Tribune-Review, the 12,703 potential civil rights violations turned down nationwide out of 13,233 total complaints from 1995-2015 include high-profile incidents in Chicago, New York and Ferguson, Missouri, but also thousands of incidents the public knows little about.

It said the most frequent reasons cited for declining civil rights complaints involving officers were weak or insufficient evidence, high standards of proof established by Supreme Court rulings, and policies set by the Justice Department.

Read more at JET.