Bad Love

Flick, one detective, met a doctor,Jack, at a party.
Flick's friend, Judy ,also works at the same hospital with Jack.
One day, Jack was dead after Jack told Flick to meet him.
Though other detective said that he had killed himself Flick tried to find a person who had killed Jack.
As ending came Flick found one girl whose brother had dead at Jack's hospital.Jack had seen THE BROTHER!(I thought the girl killed Jack because the girl thought that her brother was killed by Jack.)
(So,I thought her love for her brother means this title of book "Bad Love")But,the story continued what I had unexpected.Jack had a lot of girlfriend, one of them and Flick's friend,Judy,hadn't thought it good.
In the end , a murder is Judy.

I have read an english book "Bad Love" by Cambridge English Readers.
It isn't serious,but what a friend kills someone is sad.