I'm not sure to be honest. http://rfpose.csail.mit.edu/ is something I've come across before to detect pose of a human behind a wall.
Just found https://www.youtube.com/watch?v=IVpXeO0DYDQ - "Sense the world with TI mmWave: See through rain and walls, and detect small objects", which looks very interesting.
Ti seems to make a number of mmwave evaluation boards/chips.