From The Perry Mason TV Show Book
We catch Paul reading a copy of Lonely Hearts Calling magazine in his office.

He’s “on duty,” hired to investigate an ad placed by a lonely heiress named Marilyn Cartwright who is looking for male companionship. Or so she says. The heiress is really looking for the con man who drove her sister to suicide.

When Marilyn does find the man, Barnaby Baker, she turns on the charm convincingly. She hopes to catch him red-handed in the act of embezzlement and fraud, and turn him over to the police. Baker is murdered before Marilyn can get the goods on him. Perry’s job is to convince the police that Marilyn didn’t kill the man in an act of revenge.