Introduction Marshall P. I., Private investigator is the private detective that you call on when you need a mystery solved. Mr. Marshall is a charismatic individual that has earned a reputation for getting the job done. His background start when he graduated college, he joined the United States military where he was assigned to a special force's unit. After his enlistment he joined the City of Los Angel, California, Police Department and rose through the ranks. Several years later he decided to go his own way and start his own private detective agency. Marshall P. I.