The Hemlock Avenue Mystery by Lily A. Long audiobook.
"The Hemlock Avenue Mystery" is one of a series of mysteries written by Lily Augusta Long using the pseudonym Roman Doubleday.
A lawyer is accused of killing a rival lawyer, both having battled in court on numerous occasions. A newspaper reporter following the case is bent on determining the facts behind the murder. As it happens, there are two women also suspected of participating in the crime, and a third who was apparently utterly unconscious of what had occurred. It's up to the reporter turned detective to unravel the clues, few as they are.