April: If they are too scared to participate in the reenactment, they will just seem more guilty than ever. If they are innocent, what do they have to fear?
If they are innocent, they need to just step up and cooperate with the police. Stonewalling at this point is not wise and will just raise red flags.
Here's an example - if someone lied about that night, then they couldn't really "recreate" what they did without admitting guilt. So they have to act out something they really did not do to hide the truth. And that gets complicated, especially when the stakes are so high and you might be arrested. So all that would make someone not want to participate.
So if they have nothing to hide, they should go through with this, even if it is irritating, awkward, and sad for them. At least it is something they can do - go back to the scene of the crime and try to get closer to what happened.