Apparently, the man called 911 as his home burned in the background. He said he was sleeping when the fire started and that, in a hurry, he packed a bunch of bags, broke a window with his cane, threw the bags out the window, and carried them away. He mentioned that he had a pacemaker.
The police came to suspect him of arson. They say they found gasoline on his shoes, pants, and shirt, and they believe the fire had multiple points of origin from outside the house.
So they got a search warrant for the data from his pacemaker. That gave them a historical record of his heart rate and rhythms before, during, and after the fire.
Reportedly, the data showed that the man was active when he was supposed to be asleep, and a cardiologist has said it was “highly improbable” that he could carry out the strenuous activities he described.