It was the middle of the summer but still dark in the early mid-December morning in Whakatane, a small coastal northeastern New Zealand town, and the victim, who we will call Mary, was in bed asleep with the back door unlocked. She was waiting for her live-in boyfriend to return home after his late night shift. Two intruders entered the house intent on robbery. They stole a wallet, containing a small amount of money, and a purse, both of which were on the kitchen table. One intruder entered the bedroom, saw Mary asleep and got onto the bed with her and started fondling her breasts while his associate watched from the foot of the bed. Mary awoke and screamed. The two assailants ran off into the night, but not before Mary had grabbed the more audacious intruder and wrestled off his denim jacket, which was eventually left behind on the kitchen floor.
In the meantime Mary’s boy friend, who we will call George, returned home to find his partner on the telephone to the Police. At the same time the intruder who had got onto Mary’s bed and who had apparently been watching the house, returned, knocked on the door, and asked George for his jacket back, which he could see from the door. George, not having spoken to Mary yet, was a bit confused over what had happened and did not respond immediately. The intruder then pushed passed him, grabbed the jacket and again rushed off into the night, the jacket flapping loose in his hands. Neither intruder made any attempt to disguise themselves and the prime offender, who got onto the bed beside Mary, was soon located by a Police dog in a nearby street and arrested. He was interviewed but denied any knowledge of the incident and did not identify anyone who could have been with him. He was identified by Mary as the man who was sitting on the bed with her when she awoke, and by George as the man who had claimed his jacket back. His associate was never identified and the stolen wallet was not found, but the purse was located near the crime scene the following day. The small amount of money from the wallet was also never recovered.
The suspect was young and identified as a student. He was well known to the local constabulary. A local scene examination confirmed that the two burglars had entered an unlocked door leading directly into the kitchen. The offender was charged with indecent assault on a female, and burglary, with a potential maximum penalty of 7 years imprisonment if found guilty.
Immediately outside the kitchen
door and partly covering the entrance and path to the street was a small bush in
full flower (Fig. 1). The Police were certain
that the offender, in going through the door and down the path, would have
brushed against this bush each time he passed. The Police confirmed that bright
yellow pollen
readily came off this bush as they examined it. Four months later a control
pollen sample, originally collected 2 days after the crime was committed, was
sent to the Palynology Laboratory of the Institute of Geological and Nuclear
Sciences, where the plant was identified as
Hypericum.
Classification to species is not confirmed as no visit has been made to the
crime scene and identification from photographs is often suspect.
Fertile anthers
from the control sample, a flower from the
Hypericum
bush (Fig.
2), were
processed separately, and in isolation, from the evidential samples that were
processed later.
Hypericum
pollen turns up
occasionally in forensic samples, but documentation of over 1000 New Zealand
forensic palynology samples showed it had never been more than a trace, or maybe
1%. When someone brushes against flowering plants that release pollen easily,
the pollen often occur in clumps as well as individually in unusually large
numbers. With such large numbers and with the pollen both loosely attached and
embedded into the clothing some transfer of a few pollen grains from the prime
source, is possible. That is part of the clothing that came into direct contact
with the flowers can come into contact with other items, especially fabrics, and
transfer pollen that could not or did not come into contact with the flowers.
Thus, any item of clothing with just a few
Hypericum
pollen grains on
them
could not be used
as evidence of direct contact. However, in my experience transferral of pollen
to and from fabrics depends on the nature of the fabrics involved. Transferral
can easily occur when large numbers of pollen grains are lightly brushed onto
fabric permitting transferral to occur very soon after, before the pollen has
time to embed themselves into the material.