A conviction was unsafe where, following a blood test, a back calculation was made of the alcohol level at the time of an accident where it could not be proved that there was no possibility of alcohol being taken one hour before an accidentAppeal against conviction and sentence with leave of the single judge. At Winchester Crown Court before HH Judge Longbotham the defendant ('H') was convicted of causing death by careless driving whilst exceeding the alcohol limit and was sentenced to four years imprisonment. Two police officers attended an accident shortly after 4.50am and discovered a 99cc motorbike jammed between a telegraph pole and bushes. H was still partially astride the bike and his pillion passenger ('B') was prostrate on the ground nearby. There were no marks of braking on the road which indicated that no other vehicle was involved. B was unconscious and later died. H was seriously injured and by reason of a head injury suffered retrograde amnesia. The police made an unsuccessful attempt to breathalyse H at the scene. Later, at approximately 8.20am, a blood sample was taken which showed 64mg alcohol per 100ml of blood. On the assumption that no alcohol had been taken within the hour preceding the accident, then at the time of the accident the level of alcohol would have been in the region of 117mg per 100ml of blood, comfortably over the limit. At trial evidence was given by a couple who live close by who said that they had been awoken by the sound of a loud bang, quarrelling and possibly fighting. They contacted the police. Other witnesses, who had been at a beach party approximately a five minute bike ride away, stated that H and B had arrived late at the party as they had been watching television. They had left at approximately 3.45am. There was therefore a period of approximately one hour unaccounted for between leaving the party and the accident. The validity of the back calculation depended on the fact that no drink had been taken within one hour of the accident. The Crown therefore had to prove that no drink could have been taken. If there was a real possibility drink was taken then the calculation relied on was invalid and the jury could not safely convict. At the close of the prosecution case H made a submission of no case to answer which was rejected. H appealed against conviction on the grounds that: (i) it had not been safe for the jury to rely on the back calculation as the prosecution was unable to eliminate the fact that drink might have been taken in the hour preceding the accident; (ii) it could not be proved that H and B had not met with someone and had a drink or had bought drink from a shop; (iii) it should not be assumed that just because the motorbike left the road that was a consequence of careless driving.HELD: (1) The Crown were unable to prove both limbs of the offence as it was unable to remove the real possibility that drink was taken in the hour preceding the accident or that some other agency was involved in the accident. (2) This may be a rare case where the court was left with a lurking doubt and the conviction was therefore not safe.Appeal allowed.