The deputy discharged his or her service weapon during the incident but it wasn't immediately clear if the individual was struck by gunfire or injured in another manner.
The incident happened just after noon Friday in the area of the 28000 block of Sloan Canyon Road, less than a mile west of the 5 Freeway.
The unidentified person was "down" and in unknown condition after being shot. No other individuals were being sought. The department referred to the person as a "suspect" but it wasn't immediately clear what crime is alleged.
No deputies were injured.