Question on court procedures [New Jersey]

Factual Questions
1

Been meaning to ask this for quite a while, I just kept forgetting.

Some time back my wife and I went and saw American Gangster. A good flick based on a true story.

Russell Crowe plays Detective Richie Roberts who is investigating drug king pin Frank Lucas.

Heres the part I don’t get: at Lucas’ trial, Roberts gives the opening statement for the prosecution. Huh? Since when do cops give the opening statement?
Now, Roberts did put himself through law school while working as a cop, and he did eventually work as a prosecutor. But I can’t imagine an ADA pressing a case that he himself was going to be called as a key wittness.

I’m not sure if Roberts was being a cop or a prosecutor in the trial scene, but either way it’s screwy. They don’t/didn’t really do things this way in Jersey, do/did they? :confused:

2

Well, Wikipedia says he both prosecuted and defended him.

It looks like he was the detective on the case, passed the bar to become a prosecutor in the Bureau of Narcotics and that was one of his first cases.

3

That IS what it looks like.

But that’s absurd. He was one of the main witnesses and investigators in the case. How on Earth could he call himself to testify and ask questions to himself. It’s a very strange thing.