Some iphone 6 plus

I've found this golden iphone 6 plus with a broken glass and also bent (almost) on my dad's coat. And it isnt mine, nor my dad's, it was my dad's co-worker's phone. His co-worker had forgotten his iphone at work and then my dad took the phone from the desk and he finally gave his co-worker his iphone. Although the glass is cracked, its fingerprint sensor is still working, so does its touch screen.
The problem is that when the call is received, it doesnt play the ringtone, but it may only vibrate.
And one thing, when i saw that my dad had his co-worker's iphone in his coat, i've just though that he got this phone at work.