Here are some things to consider before going hands-on with a subject while your gun is drawn:
It’s extremely difficult to apply restraints with one hand, let alone trying to control the subject. It’s also possible the subject, once you grab him, could try to get your weapon. Not only is this dangerous for you, it causes a serious problem for responding officers. You may now find yourself in a deadly force encounter, and other officers may hesitate for fear of crossfire or accidentally shooting you.
How can this be avoided?
It is difficult to holster under stress after you’ve gone hands-on. This also places you in harm’s way. Prone the subject out looking away from you, holster your weapon, then approach if necessary. If the officer has his/her gun out and the subject flees, don’t chase with your gun out. Holster first or start calling out a perimeter on the radio.
Another option is to cover the subject with gun drawn, prone him out, and wait for responding units before you go hands-on so a back-up officer can cover while you transition to make contact.
Most importantly, provide scenario-based training to prepare your officers for these types of situations.