Couldn’t he buy a ‘burner’ phone before he went to the house? And maybe duct tape his old phone to an interstate tractor trailer?
I think the fact that burner phones makes you untraceable is a bit of an urban myth. You still need to activate the phone to use it and it will be a challenge to do that without revealing your identity or the location where you activated it from. Would not be surprised if the government had a “back door” into every burner phone sold to monitor conversations and a way to record data.