Answer
Muscles Killed Sharky
Work Step by Step
Socko and Muscles have contradictory statements, therefore one of them must be telling the truth.
This means Fats and Lefty’s statements have to be lies.
Fats claims muscles didn’t kill sharky, but we know this is a lie so muscles must have killed sharky.
We can check this by looking at muscles’ statement that lefty didn’t kill sharky, which must be the true statement.
Socko’s statement being a lie checks out, as lefty did not kill sharky.
And lefty’s statement being a lie checks out too, as if muscles was off with socko during the killing, he could not have been the killer.
