The two other officers, Richard Murphy and Kenneth Boss, fired four and five shots, respectively.
Lawyers for three of the officers - Kenneth Boss, Richard Murphy and Edward McMellon - have said that they have not decided whether to testify.
Kenneth Boss and Richard Murphy are the other officers on trial.
The taut features of Kenneth Boss, one of the officers, relaxed - almost imperceptibly, but not quite.
Mitch Garber, who is the lawyer for the fourth officer, Kenneth Boss, could not be reached for comment.
That fact may be tested anew with a federal lawsuit filed by one of the Diallo officers, Kenneth Boss.
The three officers are Richard Murphy, Kenneth Boss and Sean Carroll.
As of last July, two of them, Kenneth Boss and Sean Carroll, were working for the Police Department, though last night their current status was unknown.
"I know my son was murdered by Kenneth Boss," Lloyd Bailey, the father of the slain man, said at a news conference yesterday.
Kenneth Boss cannot remember a time when he did not want to be a police officer.