(...) Once the first pieces of blast-damaged baggage container were brought in on Christmas Eve, the police knew they were dealing with mass murder. Every piece of debris recovered, down to the smallest rag or scrap of suitcase, was logged with the precise location where it had been found.
The item designated PI/995, which became a crucial clue and a nexus for numerous conspiracy theories, was logged as being picked up near Newcastleton, twenty miles east of Lockerbie, on 13th January 1989. It proved to be a scrap of shirt collar, burned by close proximity to the explosion. Much has been written about the provenance of this item, and in particular the scanty and problematic documentation of its most significant feature – a 1 cm square fragment of fibreglass printed circuit board found embedded in the cloth and dubbed PT/35b.
This fragment is at the centre of a confused and confusing mess of renumbered pages, inconsistent dates and general muddle which have led many people to speculate that it was actually a retrospective plant. These suspicions are heightened by the absence of any record during 1989 of a serious forensic investigation of the item, although the RARDE scientists were obsessing over other pieces of circuit board at that time. PT/35b apparently sat in a side-room, unremarked, despite a photograph dated May 1989 in which it seems to sit there shouting “look at me, I’m a freaking great CLUE!”
However, detailed examination of the suspect documentation doesn’t categorically prove that any of it was inserted retrospectively. The examination notes in question, written by forensic scientist Dr Thomas Hayes, are so scrappy, disorganised and unprofessional that it’s impossible to prove anything either way. While pages 50 and 51 look very much like interpolations (PI/995 is described on page 51), there are many other equally obvious interpolations – it seems to have been the way he worked. Not only that, the nature of the documentation is such that if he had wanted to add the reference to PT/35b retrospectively he could simply have substituted a single re-written page and nobody would have been any the wiser.
One thing seems reasonably certain. The scrap of collar really did fall out of the sky, with the shirt it was part of being extremely close to the explosion. The careful logging of the recovered debris shows four separate parts of that same shirt recovered from widely separated locations which form an almost perfect straight-line continuation of the “southern debris trail”. While PI/995 itself was found in a field, PK/339 was recovered high on a steep hillside in the depths of the Kielder Forest. One piece was found fifty miles from Lockerbie, near Otterburn in Northumberland. This all fits perfectly with the known distribution of the falling, wind-swept debris, and the effort that would have been required to fake it is mind-boggling.
Was PT/35b, the infamous printed circuit board fragment, actually lodged in the cloth at that time? It’s impossible to say, but at the moment it has not been proved that it wasn’t. What has been proved is something altogether different, something entirely unsuspected during the years when the defence teams were poring over the forensic notes and wondering if certain pages might have been added at a later date.
The serious attempt to find out what the fragment was began in earnest after it was finally handed over to the Scottish detectives in January 1990. Physical and chemical analysis was carried out at the University of Strathclyde. Policemen patiently telephoned and visited manufacturers of electronic components and suppliers of raw materials. Nothing earth-shattering transpired. The raw materials were unremarkable, used in millions of gadgets and gizmos worldwide. A detailed report dated September 1990 catalogues the effort, and notes one particular feature that seemed anomalous. Printed circuit boards have a coating on the circuitry, known as ‘tinning’, applied to make the components easier to solder. In mass manufacturing this coating is almost always a tin/lead alloy, however PT/35b had a coating of pure tin, applied in such a way as to suggest this had been done by a method known as electroless plating, used by amateurs making only a few boards as a hobby.
This didn’t help though, and PT/35b’s origins remained elusive. Finally, in June 1990, the Scottish police allowed the FBI to become involved. Success was almost immediate, with no need for further analysis. With the help of a CIA agent, the fragment was matched visually to a circuit board from an electronic timer known as an MST-13 made by a Swiss firm called MEBO. Inquiries in Switzerland revealed that only twenty of these timers had been produced, as a special order for the Libyan armed forces.
This was the main breakthrough of the investigation, the cause of the switch in direction from Iran and the PFLP-GC to Gaddafi’s Libya as the prime suspects. It also provided the perfect answer to a conundrum that had plagued the investigators since early 1989. How had one of the PFLP-GC’s devices travelled on three flights before blowing up, when the triggers used by that group were altitude-sensitive? The MEBO devices were count-down timers capable of being set to go off days in advance, irrespective of altitude.
The Lockerbie investigators set off to hunt Libyans, and apparently never looked back.
Belatedly, the forensic scientists at RARDE did what they should have done in 1989, and carried out their own physical and chemical analysis of the fragment. These tests were overseen by Allen Feraday, and his notes dated 1st August 1991 record the same findings as the tests done in Scotland the previous year. The coating on the circuitry was pure tin.
There was a complication, though. The investigators by now had samples of the MEBO-produced boards for comparison, and Mr. Feraday analysed these too. They were different. They had the usual alloy coating seen on mass-manufactured products. His notes reveal some puzzlement. He recorded some tentative suggestions, but the conundrum was never resolved. The visual match with the MEBO boards was perfect, right down to an oddity in the tracking caused by the Letraset of the template not having been cut quite flush. The metallurgy discrepancy was put to one side.
The matching of PT/35b to the unique batch of timers supplied to Libya was central to the prosecution of Megrahi and Fhimah in 2000-01. With the timer off the table, proof that Lockerbie was a Libyan operation would have been absent, and the prosecution would have been in all sorts of trouble. So how was the metallurgy discrepancy dealt with in court?
It wasn’t. Mr. Feraday’s original notes weren’t disclosed to the defence, and the matter was covered by having him read out the relevant section of his fair-copy report written some months later. In that, there was no mention of any discrepancy. The report read “... it has been conclusively established that the fragment materials and tracking pattern are similar in all respects to the area around the connection pad for the output relay of the ‘MST-13' timer.”
Similar in all respects? No, it wasn’t.
None of the independent scientists who had carried out testing on the fragment were called to give evidence. The matter wasn’t brought up with the production manager from the company which had made the boards for the MST-13 timers. The fact that the composition of the coating showed that PT/35b had been made by a completely different process from the MEBO instruments was never highlighted.
Further investigation carried out by Megrahi’s defence team in preparation for his second appeal revealed that the company which made the PCBs for the MST-13 timers had never used an electroless plating technique. All the instruments supplied to Libya by MEBO had the usual lead-alloy coating on the circuitry.
PT/35b did not come from a timer sold to the Libyan armed forces, as claimed by the prosecution.
In that case, what was it? Nobody knows. The visual match between the fragment and the boards from the MEBO timers is striking, indicating that they all originated from the same template. (...)
Who made it, and why? Did it fall out of the sky that December night, or was it somehow added to the rest of the debris recovered from the shirt collar at a later date, its dodgy provenance concealed behind the smokescreen of the disorganised forensics notes? If we knew any of that, we might be a lot closer to solving the mystery of the Lockerbie bombing, still impenetrable after more than a quarter of a century.