Raspberry Jam - Carolyn Wells

This is the 11th book featuring the distinguished detective, Fleming Stone.
When a titan of industry is found dead in his locked bedroom without evidence of natural death. The doctors and the police are trying to figure out who the murder is from among the suspects. And it isn't an easy job, for each suspect either have a motive but no opportunity or have an opportunity but no motive. And to make matters worse, one of the victim's relative claims to have seen the dead man's ghost, whose appearance corresponded with a remarkable taste and smell of raspberry jam. Summary by SaraHale