WC and EC were both arrested on suspicion on Tuesday evening - 9 March. I understood that WC was not working on the date that SE was murdered -- not the date he was arrested.
Reportedly, he was off duty upon the completion of his 12-hour shift ending at 7 AM on 3 March until his scheduled return on 8 March.
MOO
When he was first arrested it was reported he had worked a cover shift 2-8pm the day SE went missing. This is covered a lot in earlier threads when posters were speculating over the routes he would have taken from Battersea etc.
Since the magistrates, this detail has changed.