of the students who found her were possible candidates for having deposited it. But surely, with what you can do now, you can compare the DNA in the semen to my DNA? If it belonged to my father, you'd be able to tell."
Lawson was beginning to feel as if he'd stumbled through the looking glass. That Macfadyen would be eager to find out anything he could about his father was entirely understandable. But to carry that obsession to the point where finding him guilty of murder was better than never finding him at all was unhealthy. "If we were going to make comparisons with anyone, it wouldn't be you, Graham," he said as kindly as he could manage. "It would be with the four lads referred to in this book. The ones who found her."
Macfadyen pounced. "You said, 'if.' "
"If?"
"You said, 'If we were going to make comparisons.' Not, when. If."
Wrong book. It was definitely Alice in Wonderland. Lawson felt just like someone who has tumbled headlong down a steep, dark burrow, no safe ground beneath his feet. His lower back pain throbbed into action. Some people's aches and pains responded to the weather; Lawson's sciatic nerve was an acute barometer of stress. "This is very embarrassing for us, Mr. Macfadyen," he said, retreating behind the phalanx of formality. "At some point in the past twenty-five years, the physical evidence relating to your mother's murder has been mislaid."
Macfadyen's face screwed up in an expression of angry incredulity. "What do you mean, mislaid?"
"Exactly what I say. The evidence has been moved three times. Once, when the police station in St. Andrews moved to a new site. Then it was sent to central storage at headquarters. Recently, we moved to a new storage facility. And at some point the evidence bags that contained your mother's clothes were mislaid. When we went looking for them, they weren't in the box where they should have been."
Macfadyen looked as if he wanted to hit someone. "How could that happen?"
"The only explanation I can offer is human error." Lawson squirmed under the young man's look of furious contempt. "We're not infallible."
Macfadyen shook his head. "It's not the only explanation. Someone could have removed it deliberately."
"Why would anyone do that?"
"Well, it's obvious. The killer wouldn't want it found now, would he? Everybody knows about DNA. As soon as you announced a cold case review, he must have known he was living on borrowed time."
"The evidence was locked up in police storage. And we've not had any break-ins reported."
Macfadyen snorted. "You wouldn't need to break in. You'd just need to wave enough money under the right nose. Everybody has their price, even police officers. You can hardly open a paper or turn on the TV without seeing evidence of police corruption. Maybe you should be checking out which one of your officers has had a sudden dose of prosperity."
Lawson felt uneasy. Macfadyen's reasonable persona had slipped to one side, revealing an edge of paranoia that had been previously invisible. "That's a very serious allegation," he said. "And one for which there is no foundation whatsoever. Take it from me, whatever happened to the evidence in this case, it's down to human error."
Macfadyen glared mutinously. "Is that it, then? You're just going to stage a cover-up?"
Lawson tried to arrange his face in a conciliatory expression. "There's nothing to cover up, Mr. Macfadyen. I can assure you that the officer in charge of the case is conducting a search of the storage facility. It's possible she may yet find the evidence."
"But not very likely," he said heavily.
"No," Lawson agreed. "Not very likely."
A few days had passed before James Lawson had a chance to follow up his trying interview with Rosie Duff's illegitimate son. He'd had a quick word with Karen Pirie, but she'd been gloomily pessimistic about getting a result from the evidence warehouse. "Needle in a haystack, sir," she'd said. "I've already found three misfiled bags of evidence. If the public knew?
"Let's make sure they never do," Lawson had said grimly.
Karen had looked horrified. "Oh God, aye."
Lawson had hoped the cock-up with the evidence in the Duff case could be buried. But that hope had died thanks to his own carelessness with Macfadyen. And now he was going to have to confess it all over again. If it ever came out that he'd kept this particular piece of information from the family, his name would be smeared across the headlines. And that would benefit nobody.