Paul Gitsham - The Last Straw

Tompkinson waved vaguely at a large pile of paper on the edge of the desk. “I’ve been trying to work out what to do with Alan’s research group over the next few weeks. The funeral is next Monday, I believe, and we hope to be up and running again by the middle of next week — assuming that you have finished your investigation now?”

“Well, as you know, we have charged somebody with the crime. Now it’s just a case of clearing up a few loose ends,” Warren said carefully. Instinctively, he was unwilling to suggest that the investigation was still open, feeling it best to keep his cards close to his chest.

Apparently satisfied with the vagueness of the answer, Tompkinson gestured to Warren to go ahead with his request.

“We’d like another quick look at the PCR room, if you don’t mind.”

“Of course. I must admit I don’t really spend much time there myself and wouldn’t really know how to drive most of the equipment in there even if I did, but I can probably show you around. It’s a shame that Mark Crawley isn’t here today. He helped design and equip the room a few years ago.” He chuckled slightly. “Alan was not impressed. Maggie Gwyer was supposed to be designing the room, but she broke her leg in a skiing accident and Mark had to take over. He spent rather more time on the project than Alan felt appropriate — probably glad of the opportunity to work away from the boss for a change.”

“Where is Dr Crawley today?” Warren asked smoothly.

“He’s at home with a migraine, poor man. It came on yesterday. He suddenly went as white as a sheet and had to be excused from our meeting.” Tompkinson’s gaze became sympathetic. “To be honest I’m amazed it took this long. The stress must have been intolerable for the poor man.”

Warren clucked his tongue sympathetically, before suggesting that they move on.

“So what is it you are looking for?” asked Tompkinson as he led them down the corridor to the small room. His walk was slow, almost shuffling, Warren observed. Assuming that the man wasn’t a great actor, Warren felt confident that their initial feeling that he couldn’t have been the killer was correct. It didn’t mean he couldn’t be involved in other ways, of course, Jones cautioned himself.

“Like I said, just a few loose ends we need to tie up. Dot the Is, cross the Ts,” Warren replied nonchalantly, repeating the cliché again.

Stopping at the door, Warren saw that the sticky blue and white striped crime-scene tape was still across the door. Slitting it easily with his keys, he stepped to one side whilst Tompkinson swiped his card through the lock. With a metallic click, the door unlocked and the familiar blast of icy cold air rushed out. The three officers exchanged quick glances, all of them thinking the same thing: that stepping into this room on a hot August evening wearing nothing but a T-shirt and thin lab coat would be uncomfortable to say the least. Spending over an hour in the room would be downright unpleasant.

The room, of course, was just how they had left it and so Karen went straight to the black PCR machine. Double-checking the sign-up sheet, she confirmed that it was indeed this machine that Spencer had booked to use Friday night.

Tompkinson moved next to her. “What are you looking for?” he enquired.

“I want to see what the last program run on this machine was.”

Tompkinson looked at her curiously. “Why do you need to know?”

“Just dotting those Is and crossing those Ts,” interjected Jones. “Would you be able to retrieve that information?”

“Sorry, Detective, I wouldn’t have the faintest idea. By the time these PCR machines were all the rage, most of the bench-work in my laboratory was being done by my grad students and postdocs. I understand the theory, of course, but I couldn’t operate one of these things.”

“Oh, hang on, this might help.” Karen plucked an A4 folder off the shelf above the machine. “If in doubt, read the instruction manual, as my dad is so fond of saying. This’ll tell us if the machine saves the last program used.” She started leafing through the manual quickly. “Here it is. May I?” The question was aimed at Warren, who simply handed her some latex gloves.

“Are you sure you know what you are doing? That’s a very expensive piece of equipment,” asked Tompkinson, looking rather uncomfortable.

“No problem. I ran loads of PCR reactions when I was at university on a machine very similar to this.”

Warren hid his smile; the young detective was quite feisty when she got going. Her personnel file had claimed that she was tenacious and not easily dissuaded when she felt she was on the right track. He had a feeling that she would go far in CID.

At his nod, the young detective started pressing buttons. Immediately the front panel and several LEDs lit up and a fan started whirring loudly. The small screen proclaimed it was running a diagnostic.

At a glance from Warren, Tony spoke up for the first time since entering the room. “This is a pretty impressive room, Professor Tompkinson. I have to admit that science wasn’t my strong suit at school. I don’t have a clue what any of this stuff does.”

Turning to the burly detective, Tompkinson smiled. “Of course, I forgot that you didn’t come in here on Saturday.”

As Sutton continued to pepper Tompkinson with questions Warren focused his attention on the PCR machine. The start-up procedure was clearly finished and Karen pressed a few more keys. The screen switched to a list of cryptic names next to what appeared to be dates. The title at the top of the screen read ‘User Log file’. Directly below that ‘TOM1 Started 2107 8/12/11 Completed’.

“If I’m reading this right, the program TOM1 was run Friday night a few minutes after Spencer swiped into the room,” said Karen, quietly.

“Can you see how long this program TOM1 would have run for?”

Pressing a few more keys, Karen called up the stored program list. The screen was arranged rather like a simple PC’s file manager with folders on the left and programs contained within those folders on the right. Selecting a folder labelled TOM revealed a half-dozen programs, numbered sequentially. Karen selected TOM1 and ‘view’. The screen immediately filled with what looked like a basic computer program. Even to Warren’s untrained eye, he could see each step of the program clearly. Karen pulled out her notepad and started jotting down numbers.

300s activate

45s melt

45s anneal

120s extension

30 cycles

300s final extension.

Shutdown

Even without doing the maths, Warren could see that the program would run for considerably longer than the sixty-eight minutes that Spencer was in the room.

“This is weird,” whispered Karen. “The last command told the machine to shut down, rather than hold the samples at four degrees Celsius until he fetched them. DNA is fairly robust, but it’s good practice to keep your samples cool or even freeze them until you need them.” She lifted each of the four hinged lids, revealing empty slots.

“And if the program did run to completion, why aren’t his tubes in the machine still? He can’t have come back down here to remove them after the run as it would probably still have been going whilst he was being interviewed.”

“Not to mention that no one has entered this room since then.” Warren stroked his chin thoughtfully. “So if Tom Spencer wasn’t in here to perform PCR, what was he doing in here?”

* * *

With Karen’s hunch looking promising, Jones decided to tackle the second question that bothered him about that evening.

Borrowing Tompkinson’s swipe card, Warren leant close to the swipe-card lock. The keypad was clearly well used, with a multitude of tiny scratches now marring the narrow slot that the card was run through. After a few seconds, Warren concluded that even if the lock had been tampered with, he’d never know; he simply didn’t know what to look for.