I can’t pin down exactly what she did with what ingredients. I can’t even be sure that she really did the things I think she did. All I have, really, are pieces of circumstantial evidence and hunches that have coalesced over the years. In my narrative of suspicions, she preferred to use vitamin A (which can cause sleepiness, blurred vision, and nausea, among other things), then she used laxatives, and then, as she got older and lazier, she moved on to prescription drugs.

Grandma never cooked the same thing twice, and her creations were greasy beyond belief and usually really weird. For example: chicken baked with apricots and canned tomatoes, or mixed-up ground meats with prunes, or pickled things. She was infamous at the local grocery store. They saved the shark livers for her.

I have never felt so strongly the presence of two contrasting characters as when I interviewed Harris. For much of the interview he performed, just as he did in court – he sang, he laughed in that exaggerated way, he whispered in that exaggerated way, he drew me a miniature flick cartoon book. Then, when he wasn’t performing, he was miserable as sin.

Whereas Clifford and Savile never appeared to question their essential goodness as men and altruists, Harris hated himself. He talked about what a useless father he’d been – selfish, paying more attention to strangers than to his wife and daughter, chasing his own dreams and desires, ignoring those of his family. He had recently written an autobiography and it had forced him to reassess his life. “You start writing it by thinking what a great guy I am. I’ve done this, that and the other. Then you suddenly think it’s all been inward focussing, only me, me, me, me, me, me, me, and people who are really close … ” I never began to suspect why he was so tortured. At the time he came across as a man with humility, in touch with his flaws. But in retrospect, I think even here he was indulging himself – only this time, it was his guilt rather than his libido

The very thing that makes true crime compelling – this really happened – also makes it distasteful: the use of human agony for the purposes of entertainment. Of course, what is the novel if not a voyeuristic enterprise, an attempt to glimpse inside the minds and hearts of other people? But with fiction, no actual people are exploited in the making.

I love crime fiction, too, but lately I’ve come to appreciate true crime more, specifically for its lack of certain features that crime fiction nearly always supplies: solutions, explanations, answers. Even if the culprit isn’t always caught and brought to justice in a detective novel, we expect to find out whodunit, and that expectation had better be satisfied.

I thought about the break-in, his absences, the dead sister, the fingerprinting . . . but what did it all add up to? Was he a victim of circumstance-or a serial killer? Was I his next target? I became obsessed with getting answers. Then I searched the most obvious place of all: Google. I typed in the name “Dino Smith,” and a couple of clicks later, there it was. His mug shot, on the America’s Most Wanted Website. He was a suspect in the biggest jewel heist in San Francisco history. I gaped at the screen in disbelief, then ran in circles, howling obscenities: “Fuck fuck fucking shit fuck fucker! Holy FUCK!”

The circumstances of Greg Fleniken’s death, as reported, were unremarkable. On the table before him was a 55-year-old Caucasian male who appeared to be in decent shape. After methodical inspection, the only marks Brown found on the body were a one-inch abrasion on his left cheek, where his face had hit the rug, and, curiously, a half-inch laceration of his scrotum. This was interesting. The sack itself was swollen and discolored, and around the wound was a small amount of edema fluid. The bruising had spread up through the groin area and across the right hip. Something had hit him hard.

The story his body told grew more intriguing. When Brown opened the front of the torso he discovered a surprising amount of blood and extensive internal damage. A certain amount of partly digested food had been torn from his intestines. The doctor found small lacerations there, and on the stomach and liver, as well as two broken ribs and a hole in the right atrium of his heart.

The condition of his insides reflected severe trauma: Fleniken had been beaten to death, or crushed. Brown concluded that the wound to his genitals likely had been caused by a hard kick. He had also taken a blow to the chest so severe it had caused lethal damage. He would have bled out in less than 30 seconds.

On the official form, next to “Manner of Death,” Brown wrote, “Homicide.”

The Colt-manufactured assault rifle confirmed that, given the administration’s intention to advance gun control measures designed to curb the nation’s ready access to deadly firearms such as itself, it is becoming increasingly unlikely that the weapon will ever have the opportunity to act on its long-held desire to brutally execute even a single innocent person.

“Ever since I came off the assembly line, I’ve dreamed of being used to annihilate dozens of frantic people in a deadly rampage; it’s what I was made to do,” the semiautomatic rifle said from its display stand at Richmond-area gun retailer Pete’s Munitions. “But if the government clamps down on sales of guns like me, then I can pretty much kiss that dream goodbye. And, I have to say, the idea of that happening is massively disappointing for me.”

Savile went to work in light entertainment and thrived there: of course he did, because those places were custom-built for men who wanted to dandle dreaming kids on their knees. If you grew up during ‘the golden era of British television’, the 1970s, when light entertainment was tapping deep into the national unconscious, particularly the more perverted parts, you got used to grown-up men like Rod Hull clowning around on stage with a girl like Lena Zavaroni. You got used to Hughie Green holding the little girl’s hand and asking her if she wanted an ice-cream. Far from wanting an ice-cream, the little girl was starving herself to death while helpfully glazing over for the camera and throwing out her hands and singing ‘Mama, He’s Making Eyes at Me’. She was 13.

There’s something creepy about British light entertainment and there always has been. Joe Orton meets the Marquis de Sade at the end of the pier, with a few Union Jacks fluttering in the stink and a mother-in-law tied in bunting to a ducking-stool. Those of us who grew up on it liked its oddness without quite understanding how creepy it was. I mean, Benny Hill? And then we wake up one day, in 2012, and wonder why so many of them turned out to be deviants and weirdos. Our papers explode in outrage and we put on our Crucible expressions before setting off to the graveyard to take down the celebrity graves and break them up for landfill. Of course. Graffiti the plaques and take down the statues, because the joy of execration must match the original sin, when we made heroes out of these damaged and damaging ‘entertainers’. We suddenly wish them to have been normal, when all we ever ask of our celebrities is that they be much more fucked up than we are. And what do we do now? Do we burn the commemorative programmes, scratch their names from the national memory?

After the arrest, the gossip centered less on Mack than it did on Betty. “She was seen as a slut and a diabolical manipulator,” says Shelton Williams. “My father overheard a customer at his car wash say, ‘Everyone knew that girl was no good. She tricked that boy into killing her.’” Betty’s classmates in Winterset, which was canceled after the news of Mack’s arrest, puzzled over her intentions on the last night of her life. Had she really wanted to die, or was she still hoping, somehow, to win Mack back? “I think Betty trapped herself in a real-life drama of her own making,” says Dixon Bowles. “She was ad-libbing all the way, and it spun out of her control. I remember a teacher taking me aside afterward and asking me, ‘Was Betty pregnant?’ And I said, ‘No. I wish it were that simple.’ It was a game of chicken, and she never backed out.”

People have often asked me if the Monster of Florence will ever be found. I once believed that Spezi and I could find the truth; now I am not so certain. Any crime novel, to be successful, must contain certain basic elements: there must be a motive; evidence; a trail of clues; and a process of discovery that leads, one way or another, to a conclusion. All novels, even Crime and Punishment, must come to an end.

But life, I have learned, is not so tidy. Here were murders without motive and a trail of clues apparently without end. The process of discovery has led investigators so deeply into a wilderness of falsehood that I doubt they will ever find their way out.