Chapter 12
TheFirearms Discharge Residue test, shortened to FDR, is a simple swab that shows whether fused particles of barium, antimony and lead, invisible to the naked eye, are present. A positive test indicates a gun has been fired.
Poe knew FDR was a limited form of evidence. It wasn’t infallible, it wasn’t a literal smoking gun. There were numerous ways to get a false positive. Residue from brake pads, fireworks, arc welding and even key cutting had all been incorrectly identified as FDR.
But it didn’t look good.
‘Where?’ he asked.
‘On her hands,’ Lee replied. ‘The responding cops put them in forensic paper bags and secured them at the wrist as a precaution. I had CSI swab her when I started questioning the evidence. Further analysis revealed it was an exact chemical match with the residue we took from the victim.’
‘You used gel swabs on her eyelids? Took hair combings?’
‘We did.’
‘And?’
‘Negative.’
‘None on her clothes either, I take it?’ Poe said. ‘You’d have mentioned it if there was.’
‘There wasn’t. But it looks like a small-calibre weapon was used. There wouldn’t have been much blowback.’
Poe paused. ‘You haven’t got the gun yet, have you?’
‘Not yet.’
Poe made a mental note of this. Juries didn’t like it when the prosecution couldn’t provide the murder weapon.
‘Anything else?’ he asked.
‘I’m afraid so. And it’s the big one. Nothing that can be easily explained.’
‘Go on.’
‘It snowed for an hour yesterday afternoon. Started at three, an hour and a half before Professor Doyle left work. Didn’t thaw until today.’
‘So?’
‘Professor Doyle arrived at her father’s at six p.m.’
Poe waited.
‘Rigor hadn’t yet set into the victim’s face or hands when the FME arrived.’
‘And?’
‘And there was only one set of footprints going into the house. Hers. They went from her car to the front door. There were no other footprints in the snow anywhere around the house. No one climbed out of a window and no one walked out of the back door.’
Poe sighed. This was bad.
Rigor mortis, or post-mortem lividity, was the stiffening of the corpse caused by chemical changes in the muscles. It started in the face and hands within two hours after death and was usually complete within six. Elcid Doyle had been dead for less than two hours when he was discovered, which meant he’d been killedafterit had snowed, not before. This was a big problem if the only footprints outside the house were Doyle’s.
‘The snow hadn’t covered any other prints?’ he asked.
Lee shook her head.
‘It only snowed for an hour and it wasn’t heavy enough. Barely a centimetre.’