A dairy worker murdered execution style nearly two weeks ago.
Two cameras at the Madera County Dairy helped investigators gather clues.
Video also assisted police to identify Nevada Rodriguez.
They say she's connected to the suspect in an attack on two officers on Wednesday afternoon.
Earlier in January a Fresno police surveillance camera witnessed a suspect in a light colored sweatshirt ... Approach a couple.
They started to run ... as he began shooting.
These surveillance cameras are installed by people like Alex Daley.
He says most businesses don't rely on video to capture major crimes.
Alex Daley, Surveillance Integration "For the most part it is small crimes and it's inside activity that they are usually working to detect. Obviously nobody is hoping for an event like that."
Surveillance cameras have come a long way. Now that can be hidden like this nondescript box. Right here is a camera. It's so powerful, it can capture a license plate number about 3-hundred feet away.
Daley: "You can make easy identification of individuals ... license plate identification off of individuals."
Some of Daley's cameras can even identify a person walking in a parking lot.
Investigators say this could be valuable evidence when tracking down a criminal.
Police are deploying more cameras to patrol Fresno streets.
Dan Scroggins describes the PELCO camera that taped a man being shot.
Dan Scroggins: "It's also discreet. When it's installed it is difficult to tell where the camera is pointed right because it is encapsulated in an enclosure with a bubble on it."
Scroggins expects surveillance cameras to grow in numbers, evolve and continue to serve as a tool for police and private citizens.