A district attorney’s office in Texas is investigating accusations that a Houston-area abortion doctor killed babies who were born alive at his facility. The pro-life group Operation Rescue told authorities that former employees revealed to them that Dr. Douglas Karpen preformed illegal third-trimester abortions and killed babies who survived the initial procedure. The investigation comes just days after Philadelphia abortion doctor Kermit Gosnell was charged with several counts of killing live babies in a high-profile murder case …