Bad Moon Rising
Believe it or not, I've had that happen.What could cause 2 tires, front and rear, to be punctured in the sidewalls at the same time, that might be an accident?
We worked it out as follows: we were in a Chevy Tahoe out past a farm in Colorado. Part of the gravel road ran through a rocky slab-based section that had dirt roads through broken rock slabs. The dirt roads were lower in places than the rock slabs on both sides of the tracks.
We figure both front and rear tires on the right side must have slid along one of the rock slabs while we were driving through that area, and the impact perforated the sidewall but not entirely - the 'crease' from impacting the rocky slab created a slow leak in both front and rear tires.
We parked back at the house, came out a bit later, and both the front and rear tires on the right side were flat.
I wouldn't have believed it had it not happened to me.
I'm not saying you weren't the victim of an attack, but I'm relating that something like that happened to me and it wasn't an attack - just an encounter with sharp rocks.
The weird thing about your situation is when you say your car never left the garage. If so, then someone came into your garage and damaged the tires.
In these "neighborhood issues" cases, the very best thing is often security cameras. Obvious ones and not-so-obvious ones. Nothing is as pursuasive in court as video of an event occurring.
Sorry you are dealing with this.