The Mendoza Line (case)

A baseball player was killed with the blow of a 90 mph baseball to the head. Accidental or deliberately, the CSI's are called in to help find out whether it was a homicide or just a freak accident.

WALKTHROUGH
If you have a walkthrough for this case, please post it here. List all locations for evidence.

*SPOILER* Whodunnit?
"Lefty" Mendoza was, indeed, murdered, but not because of the 90-mph baseball. Mendoza had been poisoned by the Club House Manager because the CHM's wife was having affairs with Mendoza and, in return, the CHM felt the need to poison Mendoza. The CHM was arrested.