Auto-motive.
Forensic Files - 2000 Auto-Motive was released on: USA: 29 April 2011
a motive is something a criminal has
Miami Undercover - 1961 Auto Motive 1-25 was released on: USA: 9 July 1961
identifying a motive is seeing why the person committed the crime.
I am assuming you mean as in "motivation." Motive means the determination of a certain phenomena that is not obvious.
the reasons for the characters actions in a story
A by-motive is a hidden motive.
it means to eat an ancient fruit
An ulterior motive is a motive that they have beyond the main motive. They often do not show that they have this motive and it is often not good. The ulterior motive is almost always has it for their own good only.
An ulterior thought is a hidden or unstated intention behind someone's actions or words. It refers to a motive or objective that is not openly expressed.
With a motive other than the ostensible and proper one.