Let us frame things: Mr. Menezes was pinned, immobilized, to the ground by ununiformed police.
My town is famous for justifying murder by police. Last week our local police shot dead a 13 year old girl (black, of course) for "menacing" them with a can of spray paint. An acquaintance of mine remarked that town police use more deadly force than that permitted to the US miltary. That's saying something! Unnecessary force coupled with the perverse attitude of absolving the police from inappropriate conduct and action has its champions in Britain, too:
London Mayor Ken Livingstone absolves police: This tragedy has added another victim to the toll of deaths for which the terrorists bear responsibility.
Glen Smyth: Police officers in these circumstances are expected to make split-second decisions that have life-long consequences.
Home Office washes its hands: It was an operational matter for the police.
As to the police work required to nab suicide bombers, these people don't just get up in the morning and say, Gee it's a great day to bomb the London Underground. I think I'll get that suicide vest out of the basement! No, no, no! They discuss. They plan. They use stealth. Their plot evolves incrementally, over months and sometimes years. What is needed is human intelligence--within the community. Not a gang of cops in scruffy plain clothes from the suburbs profiling dark-skinned urban men attired in baggy outfits and then shooting them in the head point-blank--a nice little recommended tactic from Israel and a convenient endrun around Britain's long-standing legal tradition of habeas corpus.
Update: Did Tony Blair really say this? "Our men will continue, if necessary, to shoot suicide bombers, aiming for the head. But, shooting them in another part of the body is okay too, if it keeps them from carrying out their deadly mission." What kind of dumbass micromanaging is that? The point is, the headshot is Israeli operating procedure adopted by Operation Kratos allegedly used to prevent a suicide bomber from detonating his payload. (Not that it has ever been very successful). I should like to inform Mr. Blair that the error is the hysterical, profiled, and circumstantial grounds on which deadly force is used.