i got stuck so i printed out TLC w/t it said to get blood off nathans shoes. how do i do that. thanks

Did you do this already:

Take picture of bloody foot print near victim’s leg.
Get close-up of victim’s face to get a blood sample.
Click on blood splatter on the wall, take picture.
Click on the blood splatter again to get blood sample.

I think that this - the first action especially - should trigger asking Nathan for a sample of the blood from his shoes.