Two men conspired to rob the North Hollywood Bank of America in 1997. The day in which the two conspirators carried out their plans, their conspiracy to rob Bank of America became plans set into motion. Their plans also failed.
There are certain unknown factors of their plans in which an individual whom heard certain details in the story might entertain questions they felt were left unanswered. These unanswered questions lead invoke the natural human inclination to seek answers to such questions. When no definite or satisfying answers are found, the human mind has a creative tendency to begin filling in the blanks based on what information is available. The theory that fills the unfulfilled element of the story hopefully satisfies the quest for an answer and logically fits within the context of other known facts regarding the case.
In the case of the 1997 NoHo bank robbery attempt, the two conspirators were understandably dead after the shoot-out they provoked with LAPD. Any questions that could not be answered by evidence found on their person or at their dwellings went to the grave with them. Also, any answered questions a person with interest in the case would have to be answered through logical deduction based on other surrounding evidence. Finding out the structure behind the story is much like being a good detective or the currently and seemingly dead art of good investigative reporting. The idea is to suggest for consideration logically deduced conclusions to an audience, be that in court proceedings or to a news reading audience.
What a conspiracy theory ought to do is entertain an avenue that is a potential truthful account regarding an event or circumstance that is left undefined. It conspires to discover the truth.