A criminal is by definition someone convicted of a crime by a court of law.
We seem to be talking about the rights of the suspected criminal before the judicial process is complete.
Arrest: this is the point of apprehension and the first time the 2 parties come together. The level of force involved in this must be proportional to the level of resistance / risk , but must always be reasonable.
the shooting of the London Bridge terrorist was deemed reasonable as he was wearing a bomb vest, the fact that it was later found to be a fake is not a defence.
The prisoner will be fed, watered and given medical care if necessary, the police must be allowed to do their job and if the prisoner resists or is violent, then suitable force can be used to subdue them.
Once a prisoner has been charged then a judge will decide on remand or bail, restrictions etc,
At this point the prisoner is not convicted but is in the judicial system
All of this is well known and shouldn’t be a surprise to anyone.
I think the crux here is the level of force on arrest.
Police dogs would only be sent in to subdue someone who was a threat to others or to the arresting officers.
The independent police complaints authority will investigate any issues raised, that’s what they are there for.
Police officers have to work within the law, but they are human and sometimes placed in potentially dangerous situations where a split second decision is needed. Hind sight is a wonderful thing, but sometimes it is necessary to stand in the shoes of the police.