In what ways might Macbeth's state of mind and behavior in Act Three be similar to those of criminals today? Cite evidence to explain your response.
Think about present-day explanations of the behavior of criminals
In Act III, Macbeth is driven seek out and destroy Banquo and Fleance out of what he believes is necessity. The prophecy of Banquo's sons becoming kings is still looming over him. The power of suggestion was just as strong in Shakespeare's day as it is ours.
If you think about Act III and the motivation for Macbeth's choices, you start to see similarities. Macbeth is consumed - you see it all the time in movies when a character (normally the bad guy) gets so preoccupied with his own ascension that he loses all touch with reality and sense. Macbeth is tempted by external forces who suggest to him that he will be all of these great things. (Side note: Would Macbeth have been those things without these suggestions? Or rather, do the suggestions put the idea in Macbeth's head?)
Today's criminals seem to operate in the same fashion. Oftentimes, they are driven by external forces - pressure, suggestion, force, revenge, etc. They are also motivated by some of the same internal forces as Macbeth - greed, ambition, a thirst for power, desperation, suffering, and so on.
Refer to eNotes character analysis of Macbeth for more. It'll get you headed in the right direction. After that, you should be able to think of modern-day examples that are similar to Macbeth either in motivation or choices at least.
I hope that helps get you started!