Philadelphia (CNN) -- The defense in the murder trial of a Philadelphia doctor accused of performing illegal late-term abortions rested Wednesday without calling any witnesses.
Closing arguments in the trial of Dr. Kermit Gosnell are scheduled for Monday, and a jury could begin deliberations Tuesday.
Gosnell, 72, is charged with four first-degree murder counts for the deaths of four babies. Authorities allege that some of the infants were born viable and alive during the sixth, seventh and eighth months of pregnancy, but were killed with scissors that were used to cut their spinal cords.
In Pennsylvania, abortions past 24 weeks are illegal unless the health of the mother is at stake.
Defense attorney Jack McMahon has maintained that none of the infants was killed; rather, he said, they were already deceased as a result of Gosnell previously administering the drug digoxin, which can cause abortion.
McMahon cross-examined the state's witnesses Wednesday, but did not call any witnesses for the defense.
Gosnell also is charged with third-degree murder in the death of a 41-year-old Virginia woman, Karnamaya Mongar, who died of an anesthetic overdose during a second-trimester abortion.
Gosnell, who operated the Women's Medical Society clinic in West Philadelphia, has pleaded not guilty.
On Tuesday, Common Pleas Judge Jeffrey P. Minehart threw out three of the original seven first-degree murder charges against Gosnell as well as five abuse of corpse charges in connection with the storage of the feet of aborted fetuses. Minehart also dismissed one count of infanticide, the intentional killing of an infant.
A grand jury investigation determined that health and licensing officials had received reports about Gosnell's practices for two decades but had taken no action, Philadelphia District Attorney Seth Williams said.
When authorities searched Gosnell's office, they found bags and bottles holding aborted fetuses scattered throughout the building. Jars containing the severed feet of babies lined a shelf. Furniture and equipment was bloodstained, dusty and broken.
The city's chief medical examiner, Sam Gulino, told jurors this month that as part of the investigation into the charges against Gosnell, he had to examine the remains of 47 aborted fetuses that were stored in water jugs, pet food containers and a freezer inside the abortion clinic.
Minehart also dismissed six of the nine counts of theft by deception against Gosnell co-defendant Eileen O'Neill, 56, a medical school graduate who worked as a doctor at the Women's Medical Society.
O'Neill, who did not have a medical license, is not charged with performing abortions but with participating in the operation of a "corrupt organization."
Meanwhile, a gag order remains in place preventing attorneys or the jury from speaking to the media.
If found guilty, Gosnell could be sentenced to death.