In the early days (centuries to be precise) catching a thief or identifying the criminal was a very difficult job. Investigators, literally, had to wait for the criminal to confess his/her crime!
Without the aid of proper technology or techniques, this was a very taxing work. Life was so hard without the camera (well at least for these investigators). The daguerreotype process of photography was invented earlier in 1839 but was not used until 1870s by the french to identify the victims!
The scientific know-how of the photo capturing has evolved many folds, but the process of crime scene photography has remained fairly similar(60%...almost).
These photographs depict the strangeness of the work done by police in the early times.
Have a look for youself!
So much hardwork ?!?!