The case involves a sexual assault allegation by Nicola Graham against Maurice Johnson. Nicola claims the assault occurred in an alleyway on December 18, while Maurice claims they had consensual sex in his bedroom on December 15. Forensic analysis found significant fibers from Maurice's home on Nicola's clothes, as well as semen, supporting Maurice's version that the encounter occurred in his home. The persistence and transfer patterns of the fibers and semen indicate the sexual activity likely took place in Maurice's home, not in the alleyway as Nicola claimed.

1. Case study
INTRODUCTION: Every contact or activity leaves one forensic evidence types or the other.
Scientifically recognising and recovering measureable quantity that can benefit forensic
analysis, provide scientific weight in criminal trial is critical. This essay aims to assess how
different evidence types transfer and persistence can assist in evaluation of case assessment
and interpretation in context of suspected sexual offence. Forensic analysis of semen, saliva,
fibre, hair, blood, and stool has different evaluative weight depending on case assessment
and interpretations. Every forensic evidence have different level, methods of transfer and
persistence depending on the materials they are deposited on, how long they stay and what
level of post transfer activities. In sexual crime, trace evidence like fibres, hair transfer and
persistence has been used to establish time frame and biological evidence of semen and
blood leads to individualisation or identification, linking crime scene reference evidence to
suspects or data base.
CASE SCENARIO: Nicola Graham adduce is been rape by Maurice Johnson along the
alleyway behind St. James stadium on the 18th December 2015 at 01:00hrs while returning
from friend’s party. She reveals that she was overcome after a long scuffle and Maurice had
penetrated sexual intercourse without condom. She reported at the Police on 18th January
at 08:30hrs and her underwear, top, dress, shirts were recovered for examination and
medical examinations done at 10:00hrs where virginal swabs taken. She reveals that
recovered items were not used or wash after the incident. Maurice was arrested in the
afternoon on the 18th January 2015 at 15:30hrs and denied the rape allegation but admitted
that they had consensual sex in his bed room at 10 Sidney groves in Fenham on the 15th
December 2015 at 00:10 before Nicola went home. At the allege crime scene, no evidence
was recovered but the following items were recovered from Maurice Johnson’s house;
duvet, the bed cover, pillow cover and the clothes he wear on the day in question. He said
that all the items recovered had been wash in the laundry machine a day before recovery.
PROPOSITIONS: Considering the above scenario, the prosecution hypothesis (Hp) that
Nicola Graham was rape along the alleyway on the 18th December 2015. The defence
hypothesis (Hd) that the sex was consented and was in Maurice Johnson’s bed room on the
15th December 2015 contrary to the complainant version of the story.
FORENSIC EVIDENCE: Both complainant and accused agrees that they have sexual
intercourse and therefore evidence that will determine when and establish where the
incidence took place is crucial. Therefore, transfer and persistence of fibres or and semen
are importance evidential type to determine the place of incident and the date.
EXPECTATION: On the hierarchy of propositions, source level of fibres and semen in relation
to establishing transfer and persistence on items recovered from the complainant, suspect

2. and the suspect house is important as describe (Gittelson et al., 2012) how probable it is for one
trace evidence tohave beentransferredduringthe alleged event,persistedonthe crime scene.Also
(Palmer and Burch, 2009) reveals that fibre evidence findings (e.g. fibre population studies) if
not considering analytical or comparison must not be used in isolation when evaluating fibre
evidence at source level.
The investigation proposition is that items recovered from Nicola would have high likelihood
presence of fibres from clothes of Maurice Johnson (if shed well) but not much of fibres
from duvet, bed shit, pillow cover and the sofa as those will be only secondary transfer in
case the incident happens along the alleyway on the 18th December. If the incidence took
place on the 15th December in Maurice house, there will be significant presence of fibres
from items recovered from his house to Nicola’s clothes as she would have had closed
contact activity on the bed and cloths were not washed. Fibres from Nicola to the bed sheet,
duvet cover and pillow cover will be presence (moderate) as due to washing.
Naturally if the incidence took place in Maurice house, there will be presence of semen or
other biological evidence profile of Nicola on bed sheet, pillowcase or duvet as the previous
contact. However this presence will not reveal how long it was deposited and investigation
will not expect semen of Nicola on items recovered from Maurice house if the incident
happens along alleyway, if presence, be very minutes as secondary transfer from Maurice.
There will be expectation of semen from Maurice to Nicola clothes in either scenario but not
much of semen Nicola on the items recovered from Maurice house as items were washed.
There will be high likelihood ratio of seeing semen from virginal swabs if the sex happens on
the 18th, provided all other factors remains unchanged that will quickly cause drainage of
the semen. No semen or very minutes is expected from the virginal swabs if the allege sex
took place on the 15th as window period for persistence would have elapse.
RESULT: Significant amount of fibres from Nicola clothes match with the duvet, pillowcase
and bedcover and moderate amount from Nicola’s clothes to same items. Semen from
Maurice with full DNA profile was recovered on the underwear and the dress of Nicola;
however no semen from virginal swabs and not much of semen from the items recovered
from Maurice’s house. Moderate amount of semen from both Maurice and Nicola
recovered from bedsheet and duvet. Source of the fibres and DNA profile from semen is not
in dispute instead, what are the likelihood of transfers of fibres from items recovered from
the house to Nicola’s clothes, how long these fibres and semen had persisted between
clothes of Nicola and the items from Maurice’s house as in (Bennett et al., 2010).
FIBRE TRANSFER AND PERSISTENCE: Fibre traces are critical in evaluation of sexual offence
cases to establish time frame after event as discussed in (Lepot et al., 2015, Vooijs et al.,
2015). Transfer and persistence of fibres between items will be lost over a period of time
after deposition depending on the texture, type and degree of contact (Szewcow et al.,
2011). This time lapses will lead to determine how long the fibres is been deposited on a
particular garments which will reveal when and where the allege incident took place linking.
To establish whether the allege sex took place in Maurice’s house or along the alleyway,
ordinary presence of fibre will not reasonably be conclusive as mentioned that even a mild
contact with a textile may cause fibre transfer (Vooijs et al., 2015) but rather transfer and

3. persistence of fibres. Fibres from the beddings, sofa, pillow cover and duvet on to Nicola
clothing significantly higher leading to reasonable conclusion that the allege sex took place
in the house as claim by Maurice. The evidential value of such trace fibres if indeed Maurice
and Nicola are complete strangers is that high presence of fibres having come from a
secondary transfer from Nicola to the house items is very low as in (French et al., 2012).
The persistence of fibres on garment depends more on time, condition of wear, surface
structure of the recipient garment as smooth surface don’t persist than on the donor fibre
type as recount (French et al., 2012). However, presence of fibres from Nicola to bed cover,
sofa, duvet, pillow cover may not be high if they don’t persistence well even the allege sex
took place in Maurice house as the items were washed. A study that observed wool fibres
reveals that it persist a little better on the recipient or garments than acrylic fibres during
the first hours of wear (Akulova et al., 2002, Palmer and Burch, 2009), therefore Nicola
clothes would still persist recoverable if it consist of wool. Also presence of fibres from
Maurice clothing used on the day of incident to Nicola would be higher in any of the
scenario but presence of other fibre from the house would be negative or very low
(secondary transfer) if the incident took place along the alleyway.
In scenario that the allege sex took place along the alleyway on the date claim by the
complainant, then there will be high presence of fibres transfer and persistence between
the complainant and the accuse as in (Akulova et al., 2002) the number of fibres found as
traces on clothes that were in contact is of the utmost importance. There will be no or very
minutes presence of fibres from Nicola clothing to any of the items recovered from the
house or fibres from recovered items of Maurice house to Nicola clothes. Presence of fibres
from any direction in this scenario significantly indicates secondary transfer and persistence
only. This means that if the complaint is said to be true, then one would expect significant
amount of fibres from Maurice to Nicola but not much fibres of items recovered from his
house.
Transferred and persistence of fibres depends on several influences, especially the nature of
both the donor and recipient garments, fibre composition and consistency of the fabric
transferability (Lepot et al., 2015, Akulova et al., 2002). Other important factors are the area
of the surfaces in contact, the number of contacts and the force or pressure of the contact
(Akulova et al., 2002). Therefore, if the allege sex was not consensual and reasonable force
used along the alleyway then there is high degree expectation of recovering high presence
of fibres from Maurice clothes to Nicola and vies versa. Structure and the texture of the
surface of garments do affect fibre persistence as smooth surface provide little binding
opportunities leads to a weak persistence “loosely bound” target and more binding
opportunities of higher persistence values “strongly bound” as mentioned in (Lepot et al.,
2015).
SEMEN TRANSFER AND PERSISTENCE: The first level in the hierarchy is source level which is
not in dispute in this scenario as both complainant and suspect admit having had sex.
Semen of Nicola on the bed cover, duvet and pillow cover will only reveal the origin but not

4. time of deposition. The arear need analysis is to look for presence of semen on virginal
swabs which will explains how long the allege sex took place. Proposition in favour of the
defence will reveal no or very insignificant presence of semen on the swabs while the
prosecution will have high likelihood (high) presence of semen. High or moderate transfer of
semen from Nicola to the bed sheet, duvet and or pillow cover or any other material
submitted will lead to reasonable conclusion that sex took place in the house. However
none or few semen transfer from Nicola to any items recovered from Maurice house will
indicate secondary transfer only from Maurice to his own house (French et al., 2012). In the
event that incident took place along the alleyway, the proposition will reveal transfer of
semen from either of complainant or suspect in both direction. Semen is believe not to be
persistence for a long period after washing, however a study prove otherwise as semen
sample achieve significant DNA profile after 8 months of storage and subsequent multiple
washing without affecting yield (Brayley-Morris et al., 2015). Therefore, there will be
presence of semen on Nicola Graham items as they were not washed or used since the
incidence as well as on the items recovered from Maurice Johnson’s house although they
will not reveal how long is been deposited.
CONCLUSION:
In my opinion base on the above case scenario, semen analysis did reveals the presence and
individualisation but not how long is been deposited on item and this will not support the
scenario explained above to answer the date that is under dispute. However, analysis of
swabs will explain how long semen could have been drained from the virginal walls,
although the window period is shorter than the fibre. There is strong support for the
assertion that the fibres transfer and persistence is evidentially on higher valued than
semen in determining when and where this alleged incident occurred which is strongly in
supportive of Maurice’s house and not along the alleyway.
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