Hair and Fiber
- The teenager was discovered wrapped in bin liners part-buried, with a plastic bag over her head fastened with a dog collar and cable ties binding her wrists and neck
- The dog collar was traced back to a particular supplier whom had sold several of the collars to a man named John Taylor.
- Similarly, the cable ties used to bind Leanne's wrists were commonly used by the Royal Mail, closely linked to Taylor's employer Parcel Force
- The twine found on the victim was particularly unusual and, following a subsequent search of the suspect's home, was found to match a batch of twine owned by Taylor, found along with more cable ties and another dog collar.
- Carpet fibers were recovered from Leanne's jumper. A search of the suspect's home revealed that he had recently removed the carpets from the house, but threads left behind on nails and underneath the floorboards were sufficient to suggest that carpet fibers at the crime scene had originated from Taylor's house.
- The investigation of Leanne Tiernan's murder also harbored the first use of canine DNA profiling in a criminal investigation in Britain after they tested dog hairs found on the body to create a partial DNA profile for the dog. However, Taylor's dog passed away since the disappearance so the evidence could not be used.
- From hair found on the scarf that was wrapped around Leanne's neck, it was possible to perform mitochondrial DNA testing, proving to be a match to John Taylor.