Who shot Frank Warren?

[Primo Carnera]

Also you gotta give Warren a lot of respect for keeping his mouth shut and not turning the gunman over to the police.

And like he says in the interview it would have been VERY easy to take revenge with some street justice but he didn't

Here's the thing. If Warren publicly stated that he knew who it was, there's no way that the Police wouldn't follow that up. If he didn't tell them, they would prosecute him for perverting the course of Justice. CPS and the Police don't go much on this "Honour amongst thieves" business.
So I don't think he did "keep his mouth shut." I think he told the Police everything he knew, they followed it up , but they couldn't get enough evidence to get a successful prosecution.
That Doesn't necessarily mean Terry Marsh, it could be someone else who they didn't have enough on to make it stick. (being very careful not to be libellous here!)
So , in a Nutshell, Frank Warren knows who it was, (or thinks he does) the Police know who it was, but can't make it stick. The case is probably closed and they're not looking for anyone else.
That's my theory anyway!

[Primo Carnera]

Also you gotta give Warren a lot of respect for keeping his mouth shut and not turning the gunman over to the police.

And like he says in the interview it would have been VERY easy to take revenge with some street justice but he didn't

Here's the thing. If Warren publicly stated that he knew who it was, there's no way that the Police wouldn't follow that up. If he didn't tell them, they would prosecute him for perverting the course of Justice. CPS and the Police don't go much on this "Honour amongst thieves" business.
So I don't think he did "keep his mouth shut." I think he told the Police everything he knew, they followed it up , but they couldn't get enough evidence to get a successful prosecution.
That Doesn't necessarily mean Terry Marsh, it could be someone else who they didn't have enough on to make it stick. (being very careful not to be libellous here!)
So , in a Nutshell, Frank Warren knows who it was, (or thinks he does) the Police know who it was, but can't make it stick. The case is probably closed and they're not looking for anyone else.
That's my theory anyway!

Oh, forgot to say, I reckon that's why there has been no Retribution or "Street Justice." the Police would know exactly where to go.