It is only a short time to get enough evidence to charge him relating to all possible offences though. The important thing is that they charged him with something otherwise they'd have to let him go.
The biggest one would have been attempted murder, but unless he actually admits to intent to kill at this point (which he obviously wouldn't do), the CPS would be unlikely to authorise it.
He could still get a very long sentence for these charges alone, especially with possible aggravating factors (drugs, age of victim).