He would still be a key witness probably the most important we'd have but we needed more time.
The committee did not hear from many of the key witnesses.
"Those are probably the two key witnesses in the case."
Which might have been the main reason she was selected as a key witness.
The prosecution has said she will be its key witness.
In the event she was one of the commission's key witnesses.
He's a key witness for our case, with a considerable record.
The prosecution's key witness told the police four different stories, and they believed him each time.
She later becomes a key witness in a murder, and the couple become closer.
Not if you are holding back a key witness from us.