[olde north church]

It's not him so the point of re-dressing him is irrelevant.
No, it's very relevant. It's that killer thing, when they feel guilt about their action they will cover someone up so as they won't be humiliated or ashamed. To save embarrassment or show repentance for their action as a form of guilt.

[lelio]

when they feel guilt about their action they will cover someone up so as they won't be humiliated or ashamed.

I think he was wearing the orange jumpsuit over his regular clothing and the killers just took it off before they dumped his body. As for why, perhaps they didn't want their fingerprints to be found. Or maybe carting around a body in a bright orange suit would attract attention.

[arasina]

I meant the photo of the decapitated body on the bridge. That was not Nicholas Berg. I have not seen any photos of his body so I couldn't tell you if it was clothed in that orange outfit.

I can only assume that the terrorists dressed Berg in the orange thing prior to his execution.