Vincent Amen, one of Jackson's ex associates and an unindicted co-conspirator, may give testimony in the Jackson trial; if the defence can persuade the prosecution to allow his limited immunity to continue.
Amen actually gave the prosecution team an interview last December. In exchange, he received limited immunity.
However, his interview with them was not what they wanted to hear; therefore they did not call him to the stand.
Now that the defence are seeking his appearance, the prosecution are arguing that the immunity is no longer on the table.
However, as with many of the witnesses, it may be that his testimony surprises both defence and prosecution.