CSA 1 - Other Physiological Fluid Types - Semen/Saliva

4 semen, how is object collected:

Labeled container

4 semen, document stain locale w/ what?

Photos, measurement, sketches

Unlike bloodstains, semen stains r not seen by what?

Unaided eye @ crime scene b/c they r hard 2 see under room/ambient light conditions, but appear as slightly yellow on light-colored fabrics/whitish on dark-colored fabrics/crusty

W/o visual aid 2 see semen stains, what common items r collected?

Victim’s clothes (SA victim underwear), suspect’s clothes, SA bedding (blankets/sheets), towels, tissue paper, car seats

2 detect semen stains, how can impractical items (unable 2 be sent 2 lab like vehicles/cars) be examined?

Screened w/ light methods, but the screening methods can fail 2 detect semen stains b/c there is detection variance upon fabric/material type w/ stain deposit, yet visual tests may not discriminate btw other physiological fluids/fluorescent contaminants

What r 2 light sources 2 detect semen stains?

Alternate light source (ALS)/Long-wave UV Lamp

Alternative Light Source (ALS - Semen Stains):

Like forensic light source, causes semen stain 2 fluoresce if viewed w/ color filter, but optimal wavelength r dependent on item’s surface trait and certain surfaces quench fluorescent reaction while an argon ion laser causes same reaction

Long-wave UV Lamp (Semen Stains)

Causes analysts 2 wear UV eye protection w/ skin covering during exam/viewing, semen stains appears on dark background, but some clothing material fluoresce (detergents/food stains), plus physiological fluids should not be exposed 2 prolonged lamp use

Semen stain collection:

Must present little disturbance 2 avoid stain transfer/swiping/contamination, gloves r worn during swab collection 2 handle/collect ctrl sample

Dry semen stain collection:

Collect entire stained item w/o flaking/dislodging, cut carpet stain (upholstery), use moist distilled water on sterile swabs then swab semen stain 2 air-dry b4 package

4 saliva, how is object collected?

Labeled container

4 saliva, document item locale w/ what?

Photos, measurement, sketches

4 saliva, common saliva evidence @ crime scene:

Cigarette butts w/ beverage cans/bottles

4 saliva, swab what 4 SA cases?

Breast/bodily areas 2 collect saliva evidence by using dry/wet swab 4 certain circumstances

4 saliva, what should be used 2 collect item w/o contamination?

Gloved hands/forceps/don’t link envelope flag, cough/sneeze on sample