25-year-old Hazrat Ali shot himself at around 2.30 PM yesterday, they said.
After hearing the bullet sound, his colleagues rushed him to the hospital where was declared brought dead, police said.
No suicide note has been recovered from the spot and it is not yet known what prompted him to take the extreme step, they said.
"Ali's family was contemplating about his marriage and he used to talk to them frequently about the same. He might have been depressed about not finding a suitable match, but we are not sure of the exact reason behind the constable's extreme act," a senior police officer said.