Up to one-fifth of Dallas police patrol cars are rolling without dashboard cameras.
The department says 15 percent to 20 percent of its 845 police cars don't have the cameras.
Officers are asking the department to not install the systems in new patrol vehicles because the cameras are so unreliable.
"The particular brand of in-car system that we have has been failing at a rate that is probably more than what it ought to, so what he have been asking for is for a moratorium on putting that system into our car," Assistant Chief Floyd Simpson said.
Simpson said the cameras are an integral part of policing.
"The resounding sentiment would be that these cameras are no longer considered luxuries," he said. "They are probably a necessity in our business."
The cameras offer a record of events that can exonerate officers from accusations -- or support allegations of wrongdoing.
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"On some occasions, it has shown us where our guys have not only shown misconduct, but in some cases has committed criminal acts," Simpson said.
"Today's cop, in this environment of transparency -- they want that system," Simpson said.
In 2009, Officer Robert Powell was highly criticized when he detained NFL player Ryan Moats on a traffic stop in a Plano hospital parking lot while the player was on his way to see his dying mother-in-law.
Powell later resigned.
More recently, Dallas police released dash-cam footage of an off-duty officer who fired her weapon in a squad car while fellow officers were trying to take her home. Police said two on-duty officers picked up Officer Kelly Beemer from a Dallas bar because she was too intoxicated to drive.
The Dallas Police Department is ready to take bids for a new dashboard-camera system, but it could be months before it gets new cameras. The city has to take bids, choose a vendor and then install the systems.
The city said it may start taking bids in a month.
NBCDFW's Susy Solis contributed to this report.
