The man advanced into the living room, where he collapsed on a sofa without uttering a word.
"So I waited a second and I said, `Did I hit you?' because I had no idea," Mize said. "He didn't move, he didn't say anything."
Keeping the gun aimed at him, Mize inched her way along her living room wall to a phone and dialed 911.
"I told them, `I have an intruder, I'm armed, and I have discharged my gun,'?" Mize said.
Within minutes, police surrounded her home. The officers on her porch told her to put down her gun, so she set it on top of an antique sewing machine she uses as a TV stand.
That's when the man tried to flee through the back door, Mize said. A police dog was there to greet him.
The man ran back into the home and police quickly followed. Mize said she watched as about five officers wrestled the man to the living room floor and the dog bit him on the leg.
"He was very strong," said Mize, a quilting and beading enthusiast who stands 5 feet 1 inch tall. "I'm really glad he didn't challenge me, because I would have had to actually shoot him."
Police identified the intruder as 35-year-old Sean Denny. He is jailed for investigation of burglary.
Denny has no felony criminal history but has 19 misdemeanor convictions, including violations of protection orders, Spokane County Superior Court Judge James Triplett said during Denny's court appearance Wednesday afternoon.
Lt. Dean Sprague said there is no indication Denny had a weapon, but he was obviously threatening.
"In this case, this guy was at least half her age and twice her size," he said.
Mize said she wasn't even sure she could fire her weapon, because she wasn't wearing her usual braces for arthritic hands. She commented to police officers that her ammo was likely older than they are.
Police said Mize acted perfectly, and gave her the junior police badge. Neighbors yelled "Yay, Sandy!" to people in front of her home Wednesday morning.
"She's a little lady, and she's soft-spoken, and she's got a great laugh," neighbor and longtime friend Brooke Plastino said. "But I wouldn't want to cross her, frankly."