To quote from https://www.txdmv.gov/sites/default/files/body-files/MVCPA_F...

Number of times an ALPR was deployed. 61,875

Number of LPR Deployments by taskforce investigators 42,878

Number of vehicles recovered from LPR detection 1,963

Number of Cleared Cases – Catalytic Converter Theft 1,658

Number of arrests from LPR detection 569

Number of identified/documented prolific catalytic converter theft offenders 266

Number of Catalytic Converter Theft bait operations 236

The problem is they don't define "deployments". There are ~13,500 ALPR cameras and they do thousands of plates per hour and neither of those numbers matches the deployment. My best guess is it is a targeted search and so a vehicle is recovered or a case is cleared 2-3 times out of every 100 times they search the database.

Regarding actual reduction, as another comment said, the amount of crime fluctuates with metal prices, pretty much lockstep. But at least they can lock the people away.