A police officer in Texas begged and pleaded with a man to drop a knife ... saying she didn't want to shoot him -- and, the moment was captured on harrowing body cam footage.
The video -- released Saturday -- captured the officer-involved shooting from February ... when a San Antonio police officer arrived at a park where a man was climbing out of a car that crashed into the lake.
It's unclear exactly how the car ended up in the lake ... but, the man -- later identified as 30-year-old Chase Deckard-Thomas -- hops out of the car with little issues.
In the clip, the officer asks the man if he's alright ... before noticing he's got what looks like a knife in his pocket and pulls out her gun.
The officer asks him repeatedly to drop the knife -- screaming at the top of her lungs that she doesn't want to shoot him. However, Deckard-Thomas keeps coming ... and, eventually she shoots him.
Local reports say the man was transported to a local hospital where he was treated for life-threatening injuries. He survived and has been charged with aggravated assault against a police officer.
We've reached out to local authorities for more info ... so far, no word back.