Monday marked the first day back from Easter break in the Mohamed Noor trial.
Noor shot and killed Justine Damond in 2017 after she had called 911 to report a possible sexual assault.
The defense is focusing on what the officers described as a startling slap on the back of their car.
Testimony on Monday focused on the process by which the officers' squad car was searched, and why it was in different investigative hands at different points.
It included sworn testimony from a fingerprint specialist, who says none of the many prints lifted from the car was Justine Damond's, and some were too smudged to identify.