While he's only charged with killing seven live babies, prosecutors believe Gosnell killed hundreds of infants and destroyed related records, according to a grand jury report.
During the trial, ex-clinic employee Stephen Massof testified he "snipped" babies' spinal cords to kill them after delivering them live.
"It would rain fetuses," Massof said, according to NBC10 Philadelphia. "Fetuses and blood all over the place."
Sherry West, another clinic employee, testified Monday that one newborn at the clinic was 18 to 24 inches long when it was killed, the Philadelphia Inquirer reported.
"It didn't have eyes or a mouth but it was like screeching, making this noise. It was weird. It sounded like a little alien," she reportedly testified.
Gosnell is accused of killing seven newborns and a 41-year-old refugee from Nepal who was getting an illegal late-term abortion. He was charged with murder in January 2011 after a grand jury handed down a graphic and disturbing 281-page report on his case.
"When you perform late-term 'abortions' by inducing labor, you get babies. Live, breathing, squirming babies. By 24 weeks, most babies born prematurely will survive if they receive appropriate medical care. But that was not what the Women’s Medical Society was about. Gosnell had a simple solution for the unwanted babies he delivered: he killed them. He didn’t call it that. He called it 'ensuring fetal demise.' The way he ensured fetal demise was by sticking scissors into the back of the baby’s neck and cutting the spinal cord. He called that 'snipping.'"