If you were a prosecutor, what would you be most likely to do to convince the jury that the defendant is guilty?

I believe the answer is: .Have an eyewitness testify that she saw the defendant commit the crime.

Even though direct eyewitness is  strong influence for the juries, in this day and age, it's not regarded as the strongest proof for the case.
In modern trial, footage of the crimes held the position as the strongest form of evidence to convince the juries.