Zimmerman’s attorneys have objected, and Judge Debra Nelson will hold a hearing Thursday morning to decide whether jurors should consider the new charges. The jury would still have the option of convicting Zimmerman, 29, of the second-degree murder charge that prosecutors sought when the trial began.

The last-minute maneuvering has been seen by some legal experts as an indication that prosecutors are not as confident about their chances for a second-degree murder conviction. Zimmerman, a neighborhood watch volunteer, has been portrayed by prosecutors as a wanna-be cop who shot Trayvon, who is black, after a confrontation in a gated residential community.

“They aren’t going to go all or nothing,” said Jose Baez, a Florida criminal defense attorney, of state prosecutors. “They aren’t blind to the fact that they haven’t proven second-degree murder.”