The implications of shedder status and background DNA on direct and secondary transfer in an attack scenario

DNA detection of a temporary and original user of an office space

“…As studies have reported an association between the number of contributors and the quantity of DNA retrieved [17,18]; by applying the method described in these studies and generating a correlation plot, we assessed this possibility within our study. In contrast to these previous studies, no correlation was observed between DNA quantity and number of contributors within each of the labs in our study (R 2 Linear = 3.995 × 10 -4 for Lab A and R 2 Linear = 0.088 for Lab B), as such, no further comparisons were made.…”

“…Whilst duration, frequency and manner of contact (including contact points and levels of pressure and friction) will have impacted the profiles observed [21,26,27], it is likely that the shedder status [17,[28][29][30][31][32] of the office owners and temporary occupants will also have impacted the profiles generated. For example, while the shedder status of the participants in this study is unknown, the temporary occupants of O1 and O4 in Lab A, and O1 in Lab B, were rarely present on the tested items within the offices they occupied, whereas the office owners were the sole or major/majority contributor to profiles from most items (thus the office owner may be a good shedder and/or the temporary occupier a poor shedder).…”

DNA transfer in forensic science: A review

“…-Within a work environment, DNA from co-workers is transferred to items and surfaces within a shared space during use. DNA from co-workers is transferred to the clothing worn by an individual (person A) through contact with items and surfaces within the shared space [64]. (Additional examples of indirect transfer are presented in later sections.…”

A review of trace “Touch DNA” deposits: Variability factors and an exploration of cellular composition

“…continued in research and testimony [41,42,43]. Some authors have reported increased DNA "shedding" or "sloughing" in men versus women [44], and in young males compared to older ones (the same trend was not observed in females), but significantly, over ¾ of subjects changed status (good/ intermediate/ poor) between trials three days apart [45]. Others concluded that while children are typically "better" shedders and the elderly somewhat "worse," adults in the categories in between are significantly less predictable [46].…”

“…Others concluded that while children are typically "better" shedders and the elderly somewhat "worse," adults in the categories in between are significantly less predictable [46]. Although high intra-and inter-individual variation is consistently reported [47,48], many authors report that those subjects whose handled items yield either more or better quality DNA are a quantifiable group [44,47,49,50]. No clear biological basis for this trend has been identified and initial amount of shed DNA could impact subsequent comparison of other variables influencing DNA transfer.…”