MIAMI -

A key piece of evidence in the investigation into Miami Police Officer Carl Patrick's death is surveillance video showing his girlfriend, Tiniko Thompson, 45, at a storage facility in North Miami hours after the shooting.

The video shows Thompson dropping off items from Patrick's BMW. Police say Thompson was at the facility nearly a dozen more times before coming forward with what happened inside Patrick's Pembroke Pines home.

At one point in the video, Thompson is seen talking on a cellphone. Investigators want to know whose cellphone she was using and to whom she was talking.

According to search warrants obtained by Local 10, not only has the medical examiner ruled Patrick's death a homicide, but investigators believe Thompson's cellphone may shed light into what really happened to Patrick.

Police say Patrick's cellphone was nowhere to be found when his body was discovered. Thompson's attorney maintains Patrick shot himself by accident after getting into a fight with his girlfriend.

Police say the cell phone turned up in Miami-Dade County, but they haven't disclosed where exactly they discovered it at.

Investigators have asked for a log of phone calls, as well as text and voice messages. They're also interested in looking at emails and a set of information that investigators believe will reveal Patrick's death was no accident.