The officer saw the man near East 28th Street and Portland Avenue around 2:45 p.m.
He moved toward the officer with the pipe and she tased him, but he was unfazed and walked away, said Cool.
The panhandler crossed the Northbound I-5 off ramp to Portland Avenue and the officer followed.
He charged at the officer again, hitting her with the metal pipe.
She called for assistance and fired upon the suspect, said Cool.
The suspect is in critical condition at a Tacoma area hospital.
The officer has minor injuries and will be o.k.