Last Act Test

While on duty as a municipal police officer, you observe a female and two males sitting in a vehicle parked across the street from a bank. When you get closer to the vehicle, you observe the female holding a handgun. As you are in the process of arresting the female for possession of a firearm, you observe a bank employee drive up with equipment to fix a broken ATM. Upon further investigation, you learn two things from the bank employee: that the female is a former bank employee, and that someone had tampered with the machine, which guaranteed the arrival of a bank employee to fix it.

a.) Applying the last act test, is there sufficient evidence to charge the female and her two companions with attempted bank robbery?

b.) Would the result be different if you applied the dangerous proximity to success test?

c.) Was the fact that the robbery did not take place a matter of chance, or is it possible that the three individuals may have changed their minds just at the time the officer appeared?