Can you unlock an iphone 5 to t-mobile?

So my friend found an iphone 5 at his work. I want to buy it off off him, its a Verizon so i know its already factory unlocked. But i want to know if it was reported lost can i still unlock it to t-mobile? Don't give me none of that "its stolen, report it to the police" stuff either please and thanks

If it is unlocked, you can use it on any gsm network, but you can't put it back on verizon unless you "fix" it