How to Use an Electro Static Dust Lifter for Evidence Collection

we are here at the National Forensic Academy the next process that we are going to us is the use of the electrostatic dust lifter similar to the gelatin lifter we have located a dust impression on this multi surfaced and textured background here and our goal is to remove that dust impression from the surface prior to application of the electrostatic dust lifter we would photograph with and without a scale in position and with and without oblique lighting once we know where our impression is located at we apply the electrostatic dust lifter film which is a mylar film with a black side to it so that the black side is down over the impression next what we would do is is to install the ground plate the ground plate goes approximately an inch to two inches from the film it's dependent upon whether or not the surface conducts electricity or not when you install this the next thing that we're going to do is put the charge box on top of the film and the plate if you notice on the bottom of the charge box there are three contacts this contact needs to make sure is on the back of the film and these two contacts need to make sure that they're on the ground plate when you turn the unit on if the unit arcs that is if you see electricity jumping from the ground plate to the film turn the unit off again and move the ground plate further back if when we turn the unit on as we slowly turn up the power we do not see the film draw down to the surface again turn the power off and move the ground plate a little bit closer to the film so now we're going to turn the unit on do not touch the ground plate or the film during this process there is a possibility of electric shock people with certain medical conditions should not use this unit be sure to read the manufacturer's instructions before using this in regards to medical issues so we'll turn up the unit come on you'll see the edges of the film as we turn it up draw down to the surface you can see now the edges are drawing down as soon as it starts to draw down you know that it's working properly we don't have any arcing and it's drawn down so we know that the ground plate is a proper distance from the film but what you begin to see is that there are some air bubbles in here we want all of the film to come into contact with the substrate to get the maximum amount of information back from it so we are going to use this to squeeze out the air to the edges of the film it's important that you do this gently because moving the film at this juncture could cause it to smear with a loss of information so we do not want to do that so once you're sure that you have all the air bubbles out you can turn the unit back down into an off position remove the charge box and the ground plate when we lift the film again before you package this film it's imperative that you photograph it over time this can lose its electrostatic charge and you can lose information just by storing it in a semi human environment so once you get it up make sure that you photograph this thoroughly again with and without scale the next stage is to package the item it's much like the gelatin lifter it goes into the box and is taped down on all four corners any type of shallow box if you don't have an appropriately sized the evidence box to put the film in a lot of times particularly on larger films it's advantageous to use a clean pizza box they fit very well in those when you store your electrostatic dust lifter lift here it's very important that you store in a low humidity environment humidity is the primary factor that affects the longevity of the impression

Channel: National Forensic Academy

Views: 13,957

Rating: 4.8461537 out of 5

Keywords: electro static lifter, dust impressions, shoe impressions, csi, forensics, crime scene, national forensic academy

Id: GUVzpCkFMYE

Length: 4min 31sec (271 seconds)

Published: Wed Mar 30 2016