I had a (pretty embarrassing) plot point in my WIP that someone cuts off a finger in order to access the touch ID on a cell phone, in order to access the information therein. I have googled this question, so I know the common answer is no, the iPhone uses the electric charge and the live tissue below the fingerprint. However, if the finger is hacked off immediately after death (not by the police), does all of this still apply? I assume, therefore, that the phone can't use a fingerprint alone (which would be relatively easy to get to and possibly even simulate)? The hacker - both literal and metaphorical! - is technically versed and used to computers/technology, but no world-ending genius in this regard.

Also, the phone in my WIP is never specified as being a particular iPhone because I'm sure at some point they will be replaced by something even scarier and more technical, but this phone basically is an iPhone (well, it works like an iPhone and acts like an iPhone, so therefore, it's probably an iPhone). I wondered if anyone particularly versed in technology or the science of disembodying dead fingers could help me think if there could be a way to tweak this plot point without having to throw the baby out with the bathwater, so to speak?

Thank you!