PHILADELPHIA -- A Philadelphia judge tossed three of eight murder charges Tuesday in the high-profile trial of a Philadelphia abortion provider accused of killing babies allegedly born alive at his clinic, dubbed by prosecutors "a house of horrors."

Dr. Kermit Gosnell, 72, still faces the death penalty if convicted on four remaining counts of first-degree murder involving babies allegedly killed with scissors after being born alive.

Judge Jeffrey Minehart did not explain why he dismissed the three murder counts, but apparently he felt he had not heard sufficient evidence from prosecutors that those three babies were viable, born alive and then killed.

Much of the evidence during the five-week prosecution case has come from the recollection of former staff members, though their testimony was bolstered by graphic photographs of some of the aborted babies.

Prosecutors argued the babies were viable and Gosnell and his staff cut the back of their necks to kill them.

"Why would you cut a baby in the back of the neck unless you were killing it?" Assistant District Attorney Ed Cameron asked.

Minehart upheld charges that Gosnell violated Pennsylvania's abortion laws by performing abortions after 24 weeks and failing to counsel women 24 hours before the procedure.

Gosnell also had been charged with five counts of abuse of a corpse, for removing the feet from aborted fetuses and storing them in specimen jars.