adverse witness
hostile witness

I've had no chance to call witnesses on my own behalf and no opportunity to cross-examine any adverse witness.

The Sixth Amendment guarantees every criminal accused the right to confront all adverse witnesses.

A witness called on behalf of an adverse party is usually an adverse witness.

"Wouldn't it be unusual for an adverse witness to be meeting with someone she is planning to testify against?"

Adequate notice and an opportunity to confront adverse witnesses must be afforded.

A. I don't know whether he was an adverse witness or not.

In almost every setting where important decisions turn on questions of fact, due process requires an opportunity to confront and cross-examine adverse witnesses.

He'd decided I was an adverse witness.

At trial Rainey did not testify during his side's case in chief, but he was called by the defense as an adverse witness.

This would shift the burden of producing adverse witnesses on the defendant rather than on the prosecution.