They are sometimes called Ripperologists.
With few exceptions Jack The Ripper killed prostitutes in the Whitechapel district of London located in the east end of the city. Katherine Eddows was murdered in what is known as The Mile. The Mile was policed by the City of London police while the other murders were in the Metropolitan Police jurisdiction.
The people that study ruins are archaeologist.
As far as anyone can tell, Jack The Ripper cut the throats of all of his victims first, before disembowling and mutililating them. This is what is called his MO or modis operandi, how he killed his victims. There is a very logical reason why the Ripper cut his victim's throats first. It left them unable to scream and call attention to the killer. It worked very well. For the most part, JTR worked in relative quiet.
People who study pathology are called pathologists.
People who study psychology are called psychologists.
they call him The Ripper cauz of his "acting" playing the bass! he "rips" his bass guitar while playing! xxx
pharmacologists
dictoneran
Observant.
Physiologists
Sedimentologists.
Hemographers