Episode 5.5 [Rewatch]

[Tea Lady]

I think they must have checked the body had not been reported missing by anyone and was just a suicide, probably a homeless person. Being in the Thames for sometime, probably meant it was also not in a good condition if you catch my drift. If it was a homeless person then the body would have just remained on a slab for months or years and then got a paupers funeral. Neither way is ideal but at least the person got a funeral this way.

Not sure about the key thing. Magic keys??