Not easy to figure out the owner of a locked phone.
Get the IMEI from the phone or the SIM card number and use publicly searchable records to find the phone number and service associated with.
Don't think you can scratch those off. If the phone is working even if the Sim # is scratched off you just put it in another phone and have the phone tell you the ICCID. Or again go low tech and just text yourself.
Now I have different reasons than curiosity for this type of thing. And if I found someone's phone in my car and there wasn't a good explanation of it, I would use the phone to send death threats to city council members and then destroy it or bury it. The police will be able to quickly identify the owner and will interview him.
[–] not_drunk ago
Then person will point back to real culprit with a clear motive and fellow co-worker witnesses. Bad plan by the boss.
You are assuming alot. Boss searching truck? Depends where you put it.
No risk-less choice.
Access and placement being the unknowns. This is the easiest, cheapest and pretty safe choice.
[–] 10557961? ago
They won't be able to prove the Boss had control of the device. They won't be able to implicate him without outing themselves.
Besides, this guy is the boss, he could surely fire them for their slanderous accusations.
As for finding the device, it is trivial on a rooted phone to detect local signals and with some effort triangulate them.
If you want to avoid detection then you mount the device under the car, stuffed into a suspension cavity or inside a panel like a bumper, completely covered in tar and a bit of gravel to make it match the road grime. You could buy the same device I linked but remove the housing and cram it into a piece of trash.
The game permutations are endless.