Expert Witness Work - Fatigue of Electronic Curfew Tags

Convicted (or alleged) offenders are sometimes required to wear electronically-monitored curfew tags. This is often a condition of their release from prison or as part of a collection of bail conditions imposed by the court. The curfew tags comprise two polycarbonate clips at each end of a fibre-reinforced rubber strap. The clips are retained inside a plastic housing by retaining seats. The curfew tag cannot be removed unless the polycarbonate clips are broken. In the case concerned, a subject under curfew was returned to prison after his curfew tag registered a tamper alert. He was sent back to prison on the basis of some testimony from a UK-based forensics company. The forensic scientist concluded that the subject had deliberately broken his curfew tag, in violation of his bail conditions. The appellant maintained his innocence. 

Since the forensic scientist did not consider the possibility of a fatigue type failure, despite substantial evidence to suggest it was, Double Precision Consultants were instructed by solicitors from Birnbirg, Pierce & Partners to investigate this possibility, by performing a series of systematic fatigue tests. 

One of our associates then testified against the Home Office under cross examination in the High Court about the likelihood of fatigue failures in curfew tags and the forensic evidence that might be left behind.