Motive.
identifying a motive is seeing why the person committed the crime.
Her motive to explain the way she acted was her friends.
Motive- the goal or object of a person's actions.LClemons
Character motive is what did he have against something. For example, Say your character killed someone. The dectective thinks your character is the main suspect. Once he figures out that he a suspect. The dectective tries to figure out the motive of the person. He discovers the victim has put him in his will for $1 million dollars. So the motive of the character is to get the money from the will. Motive can be anything.
profit motive
A by-motive is a hidden motive.
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.
The police are trying to find the motive of the murder.Money is my main motive.
Mainly to see if the person was known to them and to figure out if they had an alterior motive. But, IMHO it is not a good idea
motive
A person prone to steal is commonly referred to as a thief or a kleptomaniac, depending on the nature and motive behind their actions.