The root of the issue is simple. If 19-year-old Rufus McGill II dies, his parents want his memory to live. They want grandchildren.

But that concern is secondary. McGill, after all, remains on life support at Carilion Roanoke Memorial Hospital, and his parents, Jerri and Rufus McGill, hold hope their son can pull through. But if he doesn't, and hope fails, they said they want to harvest their son's sperm to start the next generation on their own.

"I just think there's a mission for his dad and I," Jerri McGill said on Tuesday. "This happened for a reason. There's no doubt in my mind that he would want this."

The ramifications of making that kind of medical decision are murky, though. While Jerri and Rufus McGill can make the decision to end life support, they can't legally collect their son's sperm. He's an adult, and they are no longer considered his legal guardians. Rufus McGill II has one full brother, who lives with his father in North Carolina, and two half-siblings.

It's an issue that places the McGills at a crossroads, where health and family law intersect with the ethical implications of starting new life without a person's expressed consent. And while post-mortem collection of semen isn't unheard of, the permutations of what happens to the child after gestation does raise red flags, ethicists say.

McGill has been listed in critical condition since Oct. 14, when he crashed his mother's 2005 Cadillac near Boones Mill in Franklin County. The wreck involved six people and killed Hannah M. Long, a 15-year-old Liberty High School student. Rufus McGill II was airlifted to the hospital.

"He took a turn for the worst last Sunday," Jerri McGill said. "They're running some tests right now, but the doctors believe he's brain dead."

She paused.

"There are some decisions that his father and I are going to have to make."

It's been a two-week nightmare for the McGills, one that has kept them camped out in a hospital waiting area since the crash.

Divorced, but still on amicable terms, the pair, both 40, agreed that keeping alive the possibility of grandchildren through their son was a positive thing. They even found a University of Virginia Medical Center urologist willing to perform the procedure, they said.

"The problem is a court order," Jerri McGill said. "We have to have a court order because of his age. We have called attorneys in Roanoke and they won't touch it with a 10-foot pole."

Thomas Hafemeister, a University of Virginia law professor who researches bioethics and the law, said the issue isn't crystal clear, that anything having to do with reproduction produces its own parallel questions.

If Rufus McGill II were a minor, the situation would be less convoluted, Hafemeister said.

"He is brain dead, but he has not yet been declared dead," he said. "The question becomes: Who is the surrogate decision maker? Who can make decisions on behalf of this adult?"

Ensuring that the child enters the world in a stable environment also becomes a concern, he said.

There may be some groups in society who find this improper, creating a life without a parent," Hafemeister said. "And what are grandparents' rights?"

Laurence McCullough, the associate director of medicine at the Center for Medical Ethics and Health Policy at the Baylor College of Medicine, said in an email that the McGills do not have ethical legal standing to make their request.

"If his wishes regarding having children cannot be reliably identified, the matter is concluded and the . parents' request should be refused," McCullough said. "There is very strong agreement in bioethics that one's reproductive rights include the right not to procreate."

If the McGills' plans to extract their son's semen do move forward, experts said the semen would then be analyzed and frozen in liquid nitrogen, essentially freezing the cells in time.

Michelle Ottay, the lab director for the Fairfax Cryobank in Northern Virginia, said she's worked with families looking to extract and freeze sperm before. The procedure is often used by military families when someone is scheduled for deployment, or when a cancer patient prepares for treatment that may affect his reproductive abilities.

And the process of creating new life through this procedure isn't cheap, Ottay said. Sometimes it can run in the six figures.

"Our experience is that typically we work directly with the patient, so they document what they want done with the sperm," Ottay said.

Susan Rubin, a clinical ethicist and co-founder of The Ethics Practice, an Oakland, Calif., firm that provides bioethics education, described the McGill case as a "complicated constellation" of issues.

"Can they do the post-mortem sperm extraction?" Rubin mused. "And . whose sperm is it? Who can choose to use it? And under what conditions?"

Rubin added that it would be reasonable for the hospital's ethics committee to consider the case prior to such a procedure.

Sitting in the hospital cafeteria Tuesday, the McGills ate among friends. Their son's former college roommate, Alex Nicklaw, 19, drove from upstate New York on Monday night to see his friend.

Rufus McGill II's friend Nikki Wright, also 19, introduced them to her family, who experienced a similar situation. In Wright's case, her niece was placed on life support after a 2011 car crash in Danville. Despite conclusions that she was brain dead, she survived to walk, talk and return to some sense of normalcy.

That story gives the McGills hope.

They said they hurt for Hannah Long's family. Even inches from their son's death, at least they have had the chance to say goodbye.

"We have people praying for him from Canada to New York to Puerto Rico," Jerri McGill said, adding that Facebook has raised awareness of their son's plight.

She said they're hoping an attorney will step forward to help them through the legalities of gaining guardianship. Until then, they wait.

"For us, we still believe. We're not going to give up on him," she said.