"It is very difficult to expect local prosecutors to successfully persecute police because relationships between prosecutors and police are so close," he said. "Federal authorities are a layer away from that, and it is much more difficult for the police...to pressure the federal authorities."

Sharpton said he learned from his work with the Louima and Diallo cases that federal courts are much more effective in dealing with cases of alleged police brutality.

He claimed that the Diallo case was severely handicapped because it was tried in state court, and he added that he encouraged the family to ask for a federal trial and appealed to the federal government to take the case.

For one thing, Sharpton noted, a defendant in the state courts of New York has the option to pick a bench trial, decided by a judge, over a jury trial, whereas in federal cases both prosecution and defense have to agree to waive the jury trial.

In bench trials, judges are more likely to rule in favor of police officers, Sharpton said.

He spoke with particular vehemence about the Diallo case, where he said the case was hurt by a change in venue from the Bronx, where Diallo was shot, to Albany. An appellate court of New York thought media coverage of the case may have swayed a jury, according to Sharpton.

"It was the most unprecedented thing I had ever seen, because the defense had already indicated that they wanted a bench trial," Sharpton said.