Did you read the entire article at the link? There was a barber as another suspect, but they called Kominski a “hairdresser”
I think most of the people who have studied the case scientifically have ruled out several suspects as having iron clad proof that it could not have been them.
Also they almost all agree it was the Polish Jew. Also of note, when he was put in a mental hospital, the killings stopped.
I did go back and finish the article after I posted it and I saw that there’s a hairdresser and a barber.
Well, Wilma Flintstone went to the hairdresser, so I guess they could have existed in 1888. :-)