Analysing knot evidence: associating innate habits with sophisticated tying tasks

Abstract Most ligature cases feature everyday, innately-tied Overhand Knots, Half Hitches and Half Knots. These knots are the result of habitual behaviour and individual tiers demonstrate consistency, except when certain contextual factors come into play. This survey focussed on comparing the chiralities of basic knots to those of Figure Eight Knots, which occur in case evidence and require similar tying actions. It is important to note that real-world Figure Eights are oriented relative to their working ends and are therefore chiral, whereas topological Figure Eights have no ends and are amphichiral. Data summarizing the tying habits of 184 survey respondents were collected and analysed. The majority of volunteers surveyed tied common Overhand Knots and Figure Eights of equal chirality, consistently or nearly consistently, irrespective of any general learning effect. A minority tied knots of opposite chirality. The knots tied by the remaining respondents varied, and the data suggested a potentially complex pattern which may be related to previous findings. Similar but less pronounced patterns were exhibited in the Half Hitch and Half Knot data. This information could be useful when analysing case evidence and making links to suspect samples, provided cautious attention is paid to context and knot function.