So the only thing I can say is, based on the yellow crime scene tape, is that LE may have turned off the heater to the driveway to preserve evidence. Also, not this home but other homes I've been to that have heated driveways, especially if they are large, is that the heating coils don't always extend right to the perimeter of the paving so there can be residual snow in some areas. When I look behind the vehicle in the image provided, through the shrubbery where the front door is and towards the ramp, the driveway is clear of snow.