LITITZ, Pennsylvania (CNN) -- The images are disturbing: A 14-year-old girl in various stages of undress; two gun-toting young men making plans to break into a house and kill everyone inside.According to a court affidavit, police found the images on computers belonging to David Ludwig, the 18-year-old Pennsylvania man charged with shooting his girlfriend's parents and fleeing the state with her.The affidavit was filed Friday in Lancaster County, Pennsylvania. In the document, Lt. Edward Tobin of the Warwick Township Police Department said two of Ludwig's laptops were being examined by a computer forensics expert.The office of Lancaster County District Attorney Donald Totaro said he wasn't commenting on whether more charges might be filed against Ludwig in light of the computer discoveries.Police searched the 18-year-old's home Sunday, a day before before Ludwig was captured in Indiana with his girlfriend, Kara Borden, nearly 600 miles from their homes.Kara is the young woman shown on the computer in various stages of undress, the affidavit said. Police have been treating her as a kidnapping victim. On Thursday, police said they had found ammunition and 54 firearms during their search of Ludwig's home.Ludwig is being held in the Lancaster County jail awaiting a preliminary hearing, scheduled for Wednesday. He is charged with two counts of homicide, one count of kidnapping and one count of reckless endangerment. If convicted he could face life in prison.Samuel Lohr, a close friend of Ludwig, told police he was aware that Ludwig and Borden were having a sexual relationship and that they frequently communicated using cell phones and computer messages. (Watch the teens' secret life -- 2:34)Detective Christopher Erb, a computer expert, has found nearly 400 pieces of possible evidence, Tobin wrote in the affidavit. Other images, besides the ones of Borden, included pictures of Ludwig with family and friends "possessing firearms and swords," the affidavit said.One video shows the two friends, dressed in dark clothing, entering a room where they handled firearms and ammunition, Tobin said. The video shows the young men leaving the house with weapons and driving to a house where they are heard planning "an armed forcible entry ... by climbing onto a roof and entering through a dormer window," Tobin says in the document.The alleged plot was never carried out."Ludwig and Lohr talked about using their weapons to shoot and kill family members inside of the residence," the affidavit says.While the two men walked back to the car, they can be heard discussing having sex with Kara and her 13-year-old sister, Katelyn, and that "the sex would constitute statutory rape and the potential to have to shoot a guy named 'Jonathan' if he found out about it," the affidavit says.Katelyn Borden has told police she witnessed the slaying of her father and then hid in a bathroom, from where she heard the shot that killed her mother. Her 9-year-old brother, David, also was in the home and ran to a neighbor's house to summon help, police said.