It may or may not be a Dog tag chain, and if it is, so what? that particular unit may have adopted the idea from the mil. for their own reasons.
At a guess, I would say it is a chain for an ID card or Warrant card holder.
FWIW, Cop-Spotters, we have now all been issued these extremely groovy blue-and-white lanyards to hang our Warrant Cards or MPS Civil Staff ID from, to assist us in working out who the phuck is who at crime scenes, on operations (etc). Some of them have the name of the Borough you work on woven into them, or "Scotland Yard" or whatever. I actually rather like mine.
that doesnt look like a G36........ the magazine is straight, not curved, and only has one lug near the bottom for clipping on to other magazines..... also what looks like the ejection port looks like it stretches the length of the receiver, and the cocking handle is nowhere to be seen. has the picture been doctored? or was it done by the paper, and they used a really bad looking toy gun?
I agree looking at the picture again it does appear to have been altered, for a start the taclight holder magically disappears, there is no ejection opening (which is orginally why I thought it was a left hand version), along the side of the body seems to have been ran over with a clone brush, and there appears to be no magazine housing the mag just merges into the body. The cocking handle which is under the sight assembly also appears to be missing. Very strange, I'm fairly sure its meant to be a G36C as you can see the gas plug protuding.
Looks like the Mail (I assume it's the Mail from [a] the typeface and the fact that they appear to have mis-identified both weapons - isn't the one on the left a G3 rather than an HK33?) has done some tinkering with the photo.
I'm assuming that this image is the same chap - identicial shirt, Lance Armstrong charidee bands, hairstyle, etc...
But look at the differences between this shot and the other one posted by EXBQMS - curved magazine being the most obvious, but taclight holder very much there too. I also can't help thinking that the shot from the Daily Mail makes the chap look as though he's just dislocated his left arm - there's something not quite right with the sleeve. Also, if you look at the edge of the trigger guard and the magazine (in the photo from EXBQMS) there seems to be a distinct photo-shop type blob that's appeared....
Just because he has a dogtag type chain round his neck, can hardly be taken as as an indication that he is in the mob.
Four years after leaving the Army, one of our Honourable Members could regularly be seen cycling though Fulham in the evening, with his dog tags and morphine gaily swinging round his neck.
These chains are used for all sorts of fashion and ID related items. I don't think this is clear and present evidence of a "smoking set of dog tags"; we're hardly working within the Geneva Convention here.
It looks like he might have hair gel on as well, perhaps he is a shakey boat?