Inspector Ghote's Good Crusade by H.R.F. Keating

Inspector Ghote is called to a murder scene.  A multi-millionaire has died from arsenic poisoning.   He knows nothing about arsenic but he knows this will be a big case.  As he investigates, his list of suspects grows...

Severn House and Net Galley let me read this book for review (thank you).  It has been published snd you can get a copy now.

There were two men who had access to the building.   One of them is a known killer.  That's who his boss wants to charge with the murder.  But he says he didn't do it and Ghote believes him.  He finds the food is left in a building that is accessible by anyone.  Did they poison the food?  He talks to the boys.  They don't tell him much.

He spends a lot of time trying to make sense of the clues he has but it doesn't seem to do much good.  He's going in circles.  Then he remembers a statement that was made.  That might be why he was killed.

Ghote does get his murderer but it takes a lot of hard work...