Basically, my steam deck recently got (presumably) stolen after accidentally leaving it at the living room (dumb move I know). I have a suspect that I believe did it but I can’t make an iron clad case against him. He:

• Claims to have been gifted a steam deck by his dad last weekend, but was only first seen with it tuesday.
• Has not been seen with a case, which is the part I still own.
• has the exact same internal storage and sd card I had
• he claims it has been bought on the Dutch equivalent of Ebay, where the prices are still comparable to brand new from valve

My mom managed to find the box, where it says the serial numbers. The numbers seem to match the suspect’s steam deck (well I think so, the caretakers did this step). But the suspect claims that not each serial number is 100% unique. I highly doubt that claim but am not a big enough expert in hardware to disprove it.

Tl;dr: does the matching serial number 100% prove it’s my stolen steam deck?

P.S: how difficult is it to revert from windowd 11 back to steam os, asking incase he did steal it cause I know his runs windows