Deadline (UK) (1983) - Amstrad CPC - Adventure, Mystery

You have 12 hours to solve the murder of Mr. Marshall Robner. If it was a murder... Mr Robner was found locked in his library, dead -- from a lethal dosage of anti-depressants. Friends and family are calling this a suicide of depressed wealthy industrialist. As Chief of Detectives, you find something just doesn't smell right about this case. You go out on a quest to find a suspect, his motive, method, and opportunity.