Hi, Davey. I don`t know all the circumstances but, the (initial) course of action by police, ie the subsequent process of attempting ID in a Group identification setting, appears a reasonable response in my view.
I`ll try not to bore you too much; if I might just say that there are literally hundreds of legal pages and rules that govern Identification issues. You mention about being 100% certain that the person spotted was the offender, that`s correct. As, potentially if a witness is unsure and/or identifies the wrong person etc, that doubt will be pushed at trial by the defence who would call the two non-identifiers, generating enough doubt to end a trial. Police can`t "un-know" that half the group couldn`t ID the suspect - they have to tell the defendant.
From what you`ve said, i`d say that police had justified grounds for arresting the person who was 100% identified by two of the witnesses. That would have led to an interview, where the suspect might, or might not have (probably the latter), admitted an offence. An admission at that stage would probably have led to a charge. Of course, a legal advisor, made available to an arrested person prior to interview, would no doubt have explained the many difficult issues with identification and a suspect might well have thought it best to say nothing at all, challenge the matter and see what CPS decided.
If visual identification was the be all and end all in the matter, the fact that two witnesses could not make an identification, could be used to seriously undermine the case.
Carrying out ID procedures is a speciality in the police due to the many complications involved. Judges throw out large numbers of cases due to doubts over identification. As such, i`d guess that someone involved in the (subsequent) formal ID procedure at Millwall`s ground would have overseen the process and would have had experience of previous, similar situations and, in particular, the threshold required to take the matter to CPS with confidence. CPS decide, on the basis of available evidence, whether there will be a prosecution, not police. (CPS threshold for prosecuting seems to have got steeper and steeper in recent years).
Sorry to be long winded, Davey. But respectfully, the fact is that matters like this are inevitably more complicated than the regular person on the street would imagine and the threshold around identification is very high. Some might say too high; some might say not high enough. If you want to delve deeper, the CPS website is the reference point:
https://www.cps.gov.uk/legal-guidance/identification#_Toc11076096
I can`t know whether the cops you dealt with could have been more robust in their investigation. If they were lacking in that regard it saddens me that you were let down and i`m disappointed for you and the lads that were attacked. The reality is that Police, like all other professions and public services, are imperfect, make mistakes and make wrong decisions. Some folk rarely come into contact with police, it`s important that cops make that contact count positively.
From personal experience, I do know that the vast majority of cops, despite being occasionally frustrated by a judicial system which a lot of the public see as overly-weighted in favour of offenders, are earnest, honest and resolute enough to keep doing their best to see violent thugs and other criminals brought to justice.
A little by-the-by; quite a long time ago I used to do uniformed police duty at Millwall`s home games. It wasn`t something I particularly looked forward to !