The appeals judges chastised Judge Jackson for those discussions but said they did not demonstrate actual bias or infect his legal reasoning.

Most US jurisdictions require a cross-examiner to lay a foundation before using extrinsic evidence to demonstrate bias for impeachment purposes.

It said the message demonstrated "clear bias" on Mr. Lessig's part.

In court documents, defense lawyers have cited several instances in which, they say, Detective Fuhrman demonstrated bias.

The judge concluded that the letter "demonstrates substantial bias and prejudice on his part against students who write for The Dartmouth Review."

The conviction was quashed on appeal as the magistrates clearly demonstrated bias.

For example, experiments using the Implicit Association Test have found that people often demonstrate bias against other races, even when their responses reveal equal mindedness.

And he demonstrated bias the past two days in how he covered both presentations.

The government said Tibaijuka had used value-laden and judgemental language, which clearly demonstrated in-built bias against it and the operation.

Two of the appeals judges said the comments were simply "candid reflections of what he had inferred from the trial" and did not demonstrate bias.