Lumia 640 jtag or chip off

New to this forum but not the cell phone world. I handle all the forensics for a police department I work for. I have a locked Microsoft lumia 640 that powers up but I need to grab the data off it. Was involved in a homicide. I’m formulary with jtag and chip off as I’ve done on Android phones. I no most phones the passcode just locks the phone not the data unless u have encryption software on it. Is possible on this phone never had a case with a windows phone yet. The typical data extraction methods won’t work. Cellbrite oxygen ect. Could I remove the emmc the connect to it and use something like atf to do a binary extraction then I’ll rebuild the data

Any help would be appreciated