In article ,
says...
Hi, I am going to start my job in mid-town Manhattan and considering
living in Journal Square in Jersey City because of the lower rent.

But I have heard of some bad saying about crimes and neighborhood of
Jersey City, so I am wondering if Journal Square is part of the bad
neighborhood.

You might consider Secaucus instead. Not much farther away (15-20
minutes into Midtown, via bus), and *much* nicer.