WIth a whopping 47 confirmed killed and a possible 200+ kills, Dr Kermit Gosnell, ran a less then legal abortion clinic.
In his clinic, mothers would moan on the floor high on drugs while free roaming cats would defecate on the floor. His furniture would be stained with blood and they would reuse needles and other one use objects multiple times. Staff members were taught and trained to lie and deceive how far along the baby was and would perform "late-term abortions" so far along that they were far from safe to the mothers. He would hire high schoolers and have them perform abortions, charging higher and higher rates for each bigger and bigger baby (and hence riskier.) His clinic offered a special one-of-a-kind "post-birth abortion" that allowed you to kill infants even after being born, This was of course, highly illegal and he charged much higher rates for these "services." For those not interested in the abortions, it was also a prescription mill that could get you a dose of just about anything they sold for the right price. If I recall, there is a 100+ page document just explaining all the illegal things he got charged with at his clinic.