Editor's note: This story was originally published Aug. 28, 2011.

Rick Haefner was brilliant. Troubled. And troubling.

A renowned geologist, the Lancaster native never held a job for long. The brilliant Ph.D. was well-dressed and well-spoken, yet was suspected of thefts, prone to bouts of explosive violence, tied up the courts with frivolous lawsuits, and terrorized neighbors near the home he'd shared with his parents on Nevin Street.

And then there was his penchant for young boys.

Haefner, who died in 2002, was described by most who met him as odd. Some used the term "sociopath."

Now, two authors are using a different term: murderer.

Last month, a book on the unsolved 1969 murder of a Penn State graduate student was published; in it, author Derek Sherwood theorizes that Rick Haefner was the assailant who stabbed 19-year-old Betsy Aardsma to death in Penn State's Pattee Library.

A second book on the crime, written by David DeKok, a former investigative reporter for the Harrisburg Patriot-News, could be published by 2013; DeKok, too, concludes that Haefner was the killer.

Officially, Pennsylvania State Police haven't reached the same conclusion. The agency terms Haefner a "person of interest" - but nothing more.

Sherwood and DeKok acknowledge that much of the "evidence" suggesting Haefner killed Aardsma is circumstantial. But it was the recollections of Rick Haefner's nephew that proved to be a "break" in the case.

Now Sherwood, whose book is titled "Who Killed Betsy?: Uncovering Penn State University's Most Notorious Unsolved Crime," says he is "95 to 99 percent sure" that Rick Haefner plunged a knife into Betsy Aardsma's heart on Nov. 28, 1969.

"Rick was a logical suspect, and the police were interested in him to some degree," said Sherwood, a self-styled Internet sleuth who has been fascinated by the case for a decade and ran a website devoted to it.

"But it wasn't until this past year, with all the [additional information about Haefner] coming out, that finally it was like - there is an end to this.

"And the end is Rick."

Shocking murder

For a few months in late 1969 and early 1970, the now-cold case burned white hot, shocking Penn State - and Holland, Mich., Betsy's hometown.

"She was a good girl, near the top of her class in high school, who might have done great things," said DeKok of Aardsma, who had enrolled at Penn State to be near her boyfriend, then a student at the Penn State College of Medicine in Hershey.

DeKok is also from Holland, Mich., and attended the same high school as Betsy. "She was six years older than me, so I didn't know her, but we had teachers in common and I remember well when her death was reported on Page 1 of the Holland Evening Sentinel" newspaper, wrote DeKok in an email.

On the surface, Rick Haefner was a charmer. "He was handsome, well-dressed, with a pleasant speaking voice," DeKok said. "But [he] was a monster - a molester of boys, again and again throughout his life. He harbored a violent rage against women that could erupt without warning."

That rage, both authors theorize, erupted in the core of Level 2 in Pattee Library, a cramped, isolated central portion of the library with long rows of books and low ceilings, called "the stacks" by students.

Betsy Aardsma was there looking for a book to complete a research paper when, around 4:45 p.m., she was stabbed once. There had been no scream; one person in the area said he'd heard a man and woman having a "normal" conversation before he heard the crashing of books and metal shelves, when Betsy fell.

Students and paramedics who rushed to her aid initially didn't realize she'd been stabbed, because she was wearing a red dress. She was pronounced dead at 5:19 p.m. - and the manhunt was on.

Police interviewed hundreds; one of them was Haefner, who told investigators that he knew Betsy - they'd lived in the same dormitory, and had gone on several dates.

Haefner, then 25, was a doctoral student in geology. He seemed a prodigy - but one, perhaps, with a dark underside.

As an undergraduate at Franklin & Marshall College, he'd worked at North Museum. "Rick was the man you would want to see walking past if you were having trouble identifying a rock or mineral specimen," Sherwood writes.

But during his tenure, specimens began to disappear from the museum. "Rick worked obsessively and was there almost every day," Sherwood writes, yet "was unable to account for the fact that the collection was literally being pillaged under his care."

Then there were the complaints from parents - disturbing reports that "the brown-haired, knowledgeable young caretaker at the museum had attempted to touch or fondle their sons when they visited the exhibits." That led museum officials to ask him to leave. Haefner denied everything.

Years later, in 1975, Rick Haefner would be arrested and charged with molesting two boys. The case, splashed all over the pages of the local newspapers, would end in a hung jury, though Judge Anthony R. Appel cited Haefner with contempt of court, fining him $500 and sentencing him to a month in county prison. Haefner served two weeks before the Pennsylvania Supreme Court ordered him released pending an appeal of the contempt citation, which Haefner won. In March 1979 the state Supreme Court ruled he couldn't be retried. His record was expunged; then he turned around and sued virtually everyone associated with the case.

Despite his pedophilic tendencies, Haefner did occasionally show interest in women - once traveling 800 miles to show up on the doorstep of a woman he barely knew to proclaim that he was in love with her. She told him to leave or she'd call the cops.

He was at Penn State on the day Betsy Aardsma was killed; he claimed to be eating dinner at the HUB Student Union when he found out about it. What he didn't tell police was that 45 minutes after Betsy had been pronounced dead, Haefner had shown up at the home of a friendly professor, out of breath. "Have you heard? A girl I dated was murdered at the library!" he said. The professor and his wife, wrote Sherwood, got the distinct impression "that Haefner may have been involved in the incident he was describing."

But without that information, police "had no reason to suspect Haefner - he was a strong student and a reasonably personable young man, clean cut and on his path to a master's degree in geology," Sherwood wrote.

Over the years police theorized about a number of other possible suspects; in his book, Sherwood tries to chase most of them down to rule them out.

Rick Haefner was the guy he couldn't rule out - particularly after he heard from Rick's nephew, Chris Haefner.

As recounted in his book, Sherwood was looking for information that might clear Rick Haefner, but found it difficult - Haefner seemed to have few friends, "and some of the people he knew didn't want to talk about him." Haefner's immediate family members were all deceased. So Sherwood began posting online, on Craigslist and in genealogy forums, looking for someone who knew Rick Haefner.

In February 2010 Chris Haefner, a local author, responded, saying that he had worked with his uncle in the "rock shop," a garage near the Nevin Street home Rick shared with his mother and father. It was where he and Chris - and the boys Rick hired - would crack and pack rocks and minerals to be sold at the Smithsonian Institution gift shop.

Chris Haefner recounted an incident that took place in 1975, after Rick had been arrested and charged with molestation. Rick was confronted by his mother, Ere, who didn't see Chris inside the shop; she "began berating [Rick] about getting in trouble again after all she had done for him to help him get out of trouble," Sherwood wrote.

Chris said Ere then screamed at Rick: "You killed that girl, now you're killing me!" Later she said: "Are you going to kill me too, Rick?"

Both Sherwood and DeKok say Chris Haefner's recollections, and other information he has shared, amount to a huge break in the case.

Contacted for this article, Chris Haefner said he has additional information that could implicate his uncle, a "final piece" of the puzzle, "key evidence" - but that he intends to keep it to himself.

Chris Haefner said he spent "hours" in his uncle's house after Rick died in 2002. "What I found in that house of his ... looking at all his personal belongings was frightening," Chris Haefner said in an email.

"Rick had a demon in him but it was innate, it was there but it was not his fault. For this he must be forgiven. For this, Betsy must now be forgotten."

Small chance.

Sherwood's book is published by Pine Grove Press, though in effect it's self-published; he began the limited liability company with a friend of the family. The book is available at Amazon.com, the Penn State bookstore and via the website whokilledbetsy.org. As of Aug. 16, the book ranked 54th in Amazon.com's "True Crime" category. And he said he received an email from a woman in Holland, Mich. - Betsy's hometown - thanking him for telling the story.

It will be told again as early as fall 2013. DeKok's book - tentatively titled "The Girl Who Was Killed in the Library: The Strange Death of Betsy Aardsma and the Forty-Year Search for Her Penn State Slayer" - was accepted for publication last week by Globe Pequot Press, a national publisher that put out his two previous books.

DeKok, who wrote about the case while at the Patriot-News, said his book will look at the lives of both Aardsma and Haefner. He said it "will explore the Pennsylvania State Police investigation that followed and why Haefner - who was briefly questioned - escaped arrest. It will then look the rest of his awful life. Finally, my book will look at the 'citizen investigators' like Derek who unearthed Haefner as the killer of Betsy Aardsma."

DeKok said he is convinced Haefner was the killer. "Rick Haefner had an inner rage against women that manifested itself again and again throughout his life," DeKok said. "It could be triggered by next to nothing." He noted a 1998 incident in Delaware, where Rick got into a verbal altercation outside a liquor store that rapidly escalated, with Rick beating the woman so badly that he dislocated her jaw and loosened several teeth.

DeKok said he will report that Betsy not only knew Haefner, but was scared of him - and told her family so.

Betsy's family has declined to speak to the press about her murder in recent years. A phone message left for Carol Aardsma, Betsy's sister, was not returned last week; previously, she told the Sunday News, "I'm not going to be able to help you."

In his later years, Rick Haefner grew ever more troubled. After his parents died, he lived in the house alone, and neighbors said the property was a mess, but that to confront Haefner about it was to incur his ire. Once he punctured a neighbor's tire with a knife; on another occasions, he picked up his dog's waste and threw it through a neighbor's car window.

There were additional run-ins with the police, including a 1992 arrest for interfering with the custody of a child after he took a 13-year-old city boy on a trip and the boy's mother reported the child missing. The case was dropped, but after the youth was placed in a group home - and Rick wasn't allowed to visit - he filed numerous lawsuits.

He also ran the Lost Dutchman Gemboree, an annual gem show that was robbed of more than $800,000 in precious stones and jewelry in 1996. In his book, Sherwood writes there is evidence to suggest Rick Haefner had something to do with the robbery. The next year Haefner canceled the show - but not before dealers had paid him for booth space, money which Haefner never returned.

In 2002 Rick Haefner died of a heart attack in the Mojave Desert, where he was studying rocks.

"How did he escape arrest?" in the Aardsma case, DeKok asked. "Mainly through dumb luck and the mass confusion after the murder. The police worked very hard and had their theories; he wasn't one of them."

State Police Lt. Leigh Anne Barrows, who is now in charge of the Aardsma case, did not return a message seeking comment.

But in his book, Sherwood writes that he spoke with other troopers who investigated the Aardsma case, who think the case may now be solved.

He also said he heard "through various channels that state police have gotten some additional information that may let them close the case, something on Rick."

Were police to finally close the case, Sherwood said it would be cathartic.

"That was always the goal," he said. "Not to write a book - but to solve a murder."

Gil Smart is associate editor of the Sunday News. Email him at gsmart@lnpnews.com, or phone 291-8817.