Jeff killed Mike!
- Jack is not the murderer, because he is the brother of the murderer.
- Ben is not the murderer, since he just met Jack 6 months ago and Jack is the brother to the murderer.
- Mike is not the murderer since he recently moved to the city.
- Dan is not the murderer since he is a younger brother. The murderer has only 1 younger brother who is Jack.
- Dan was not killed since he ran in the Marathon on Saturday.
- Jack was not killed since he has been in hiding since the crime.
- Ben was not killed since Jeff plans to install Ben’s new computer next week.
- Jeff was not killed since he is the killer.