Will Orpet was guilty. That was clear to the newspapers as his trial began in the summer of 1916, and it appeared equally clear to the people of Lake County: It took 23 days and more than 1,200 interviews to find a dozen men who said they could view the evidence impartially.
The sweltering Waukegan courthouse was packed with two distinct audiences. First were the newspapermen who came from across the country to wallow in this irresistible tale of sin and death. Second were the young women who were transfixed by Orpet's delicate, boyish features.
Tall and grave, State's Attorney Ralph Dady exuded confidence -- a fawning society columnist compared him to Abraham Lincoln -- but almost from the start, his case was plagued with trouble.
His star witness changed her story, saying that Marion threatened to commit suicide if Orpet left her for another. A classmate testified that just before Marion's death, he found her alone in a high school chemistry lab where cyanide was stored.
The prosecutor rallied with a toxicologist who said Marion must have taken the fatal dose in liquid form because cyanide residue had been found in the palm of her hand. That jibed with the theory that Orpet had mixed a deadly concoction with poison he found in his father's greenhouse.
Still, Dady knew he needed to expose the cracks in Orpet's story. So when the college student took the stand, Dady and his co-counsel were merciless, cross-examining him for 19 hours over four days.
Speaking in a cold monotone, Orpet, 21, admitted terrible things. He was a seducer, romancing and discarding a high school girl. He was a liar, denying the facts until they were thrown in his face. And he was a coward, abandoning his one-time sweetheart's body in a wintry forest rather than seek help.
Yet he remained steadfast that he was not a murderer. Marion killed herself when he told her they were through, he said. He had not given her the poison.
For all the drama of Orpet's testimony, the case turned on the testimony of three chemists hired by the defense. Marion had been killed by potassium cyanide, the kind found in her high school chemistry lab. But the poison recovered from the Orpets' greenhouse was sodium cyanide.
That was it. The jury spent five hours deliberating before declaring Orpet not guilty. He left the courthouse in triumph, wading through a flock of young women in their summer finery.
"I'm going to the country," he declared. "I've had a bad time, but my nerve is still with me. I'm just going to start in where I left off and make good. And I'm -- I'm grateful to these friends who have stood by me."
Those friends, though, swiftly dropped away. The University of Wisconsin, where he had been studying journalism, said he was not welcome to return. Local ministers called him a moral pariah. His supposed fiancee said she had no plans to marry him.
Within three months he was gone from Lake Forest. Government records indicate he became a sergeant in the U.S. Army Air Forces and served during World War I. Some stories suggest he later became an oil wildcatter and ranch hand in Wyoming. In 1920, under the assumed name of W.H. Dawson, he was briefly in trouble in San Francisco for abandoning the 19-year-old bride he had lured from Detroit.
After that, Will Orpet stayed out of the news until his death in 1948. He was buried in a military cemetery in Los Angeles.
Despite the court verdict, the story of what really happened in the woods remained a popular subject for speculation. Several national magazines recapped the case as an unsolvable riddle. Theodore Dreiser researched it while writing his classic 1925 novel, "An American Tragedy."
Coni Carfagno, of the Lake Forest-Lake Bluff Historical Society, discovered it two years ago when she was looking into the history of the property that once housed the Sacred Heart Convent. Not long after, she heard about the specter of Sheridan Road.
There have long been rumors about hauntings along that road, but a driver's account of an unearthly girl standing on the double yellow line was frighteningly detailed. Carfagno was struck by the description of the girl's damaged mouth, remembering how Marion's lips had been blistered by the poison.
So when she learned that Lake Forest College was interested in hosting a Halloween lecture on the paranormal, she suggested an exploration of Marion's story.