LITITZ, Pennsylvania (CNN) -- An 18-year-old Pennsylvania man suspected of killing the parents of his 14-year-old girlfriend Sunday and fleeing with her to Indiana made his first court appearance Tuesday. David Ludwig was flown back to Pennsylvania and arraigned on two counts of criminal homicide, one count of kidnapping and one count of reckless endangerment. Earlier, he had waived an extradition hearing.He was ordered held without bail, pending a preliminary hearing, said Donald Totaro, the district attorney in Lancaster County, Pennsylvania.Totaro said he would decide at a later date whether to seek the death penalty in the case.Ludwig's girlfriend, Kara Beth Borden, was flown back to Pennsylvania separately on a private jet, accompanied by investigators. She walked from the plane without handcuffs to an unmarked sedan and got inside.Totaro said she had been reunited with family members, and a legal guardian was appointed for her.Police have said they were still investigating the circumstances of the case to determine whether the girl was kidnapped by Ludwig or fled with him willingly.Asked if the kidnapping charge lodged against Ludwig indicated that prosecutors believe she was a victim, Totaro said, "That's correct." But he also said that "we are still investigating this case, and at this point in time, we are trying to determine what exactly happened in the home."Chief Richard Garipoli of the Warwick Township, Pennsylvania, police -- the agency leading the investigation -- said Tuesday that Borden "is the victim in this case until I hear otherwise." "She's devastated, and it's important that we put her back with her family where she belongs," he told reporters before the girl was returned to Pennsylvania.Police in Lititz, about 80 miles west of Philadelphia, discovered the bodies of Michael and Cathryn Borden, both 50, on Sunday morning. Each had been shot once in the head, police said.Ludwig was captured and Kara Beth Borden was taken safely into custody by police Monday in Indiana after a high-speed chase and crash. (Watch as Indiana police arrest Ludwig -- 1:42) Trooper David Cox, who apprehended Ludwig, described Borden as "just frantic, crying, screaming" when she emerged from the car. (Full story)Questions over extent of relationshipCourt documents made public in Pennsylvania suggested a close relationship between the two teens. The couple had been dating since May, said police there.A "close friend" of Ludwig's told investigators Monday that he was "well aware that Ludwig and Kara Borden were involved in an ongoing, secret, intimate relationship of a sexual nature," according to an affidavit used to secure search warrants for the homes of both Ludwig and Borden.The 19-year-old friend said he often spoke to Ludwig about the relationship, the affidavit said. The friend also told investigators Ludwig and Borden "often communicated via instant messages and text messages on the Internet." Their communication, according to the affidavit, included "flirtatious messages" as well as "inappropriate images of one another via various electronic media" such as their computer systems and cell phones. Each had a Web site. Borden's talked about attending prayer groups and her interest in soccer and baby-sitting.On his site, Ludwig quoted lyrics from a Christian rock band and discussed his affinity for computers and volleyball. He worked as a lifeguard and at an electronics store during the summer.Garipoli said he had not heard whether the two had a sexual relationship, but "if later on down the line the detectives in my unit find out that there was some kind of illegal activity going on, those charges will be added."Friends of the Borden family said they were stunned.The Rev. Kevin Eshleman described the Bordens as "a good family" dealing with typical teenage issues. Of Kara, he said: "I think she loved her parents.""I can't comprehend any way in which she would conspire against her parents," he told CNN. "It just is almost incomprehensible to think that she would be a part of something like that."Teen Skyler Jones described Kara as "an amazing friend." She added, "Her parents always made us feel at home at her house. It was just a nice place to be."Neighbor Tom Mannon said, "She seemed to be a typical all-American girl, just a sweet kid on the street."CNN's Allan Chernoff and Sumi Das contributed to this report.