Things got very contentious in the courtroom today in the trial of Cleveland Police Officer Michael Brelo.
Prosecutors tried to undermine defense witness, forensic criminologist Dr. Ron Martinelli.
Martinelli believes Brelo was justified in the shooting of Timothy Russell and Malissa Williams.
Russell and Williams were shot and killed in the Heritage Middle School parking lot in East Cleveland at the end of the chase in November 2012.
A group of 13 officers fired 137 shots. Officer Brelo fired 49 of those shots.
The defense is expected to end its case by the end of the week. Closing arguments are expected to begin early next week.