When a crime occurs, the first responding police officer will secure the scene and determine the need for a crime scene specialist. When a major crime against a person occurs, these specialists provide crime scene and investigative support to the police agency involved. Upon arrival at the scene, The crime scene specialist will make contact with the detective or officer who is in control of the scene. The two will exchange information about the type of crime and what processing might be most instrumental to the investigation.
Any relevant information regarding the processing of the crime scene will be provided to the crime scene specialist. of the scene is discussed before entering the scene. The crime scene specialist then makes a preliminary survey or walkthrough with the detective. The specialist will attempt to establish a path to enter and exit the crime scene, avoiding the path used by the suspect if possible. During the walkthrough, the specialist evaluates the scene and forms a plan for processing the scene and the collection and preservation of evidence.
Once the walkthrough is completed, the specialist will begin evidence collection starting with the scene. The specialist first takes video. video of the scene outside to document the location of any evidence and to show the outside premises.
The video captures the scene in an undisturbed condition. From there, they will move indoors to take video of the scene. They are trying to get an overall view of the room and also any visible evidence. After videotaping the crime scene, technicians place cones to illustrate the location of potential evidence. After the evidence markers are placed, it is time to photograph the crime scene.
Establishing shots are taken from the outside, including the address. Then three different photos are taken for each piece of evidence. One overall, one mid-range, and one close-up photo. Photographs will be taken with and without the markers.
The wide shot will include anything in the frame that could possibly be evidence, while the medium and close-ups will be more detailed photos which have been identified as potential evidence. As he photographs the scene, he is very meticulous with his shots to ensure good quality pictures. They are also careful to watch where they step, as other evidence and markers could be around their feet as they continue to photograph. To make sure he obtains all potential probative evidence, the specialist in connection with the detective discusses what crimes may have occurred. Based on the potential observable evidence and the information exchanged with the detective, this appears to be the scene of a rape and murder.
So they will be looking for bullet casings and other evidence that relate to those crimes. After the pictures are complete, a rough sketch of the premises is made, which also contains the placement of the evidence. We also do a crime scene sketch where we actually, a rough sketch, when we get back to lab, this will be converted to a formal sketch on the computer. crime scene is rough and gives approximate locations of the evidence items and then we'll do an evidence items inventory list like number two is a spent bullet number three four and five are spent We'll list all those there.
We'll take two walls and measure every piece of evidence from those two walls. So then if we ever want to put that evidence back in place, we can have a cross section. That way we know where the evidence goes back. A laser measuring device is used to establish the coordinates of each item. 8 feet, 15.6, 2.5.
5 foot, 111. The evidence is collected in a certain way so that contamination is not possible. Everything is labeled by evidence item number and what it is. That way we don't get confused if we got three shell casings on the floor.
Just because they're all the same caliber doesn't mean they all came from the same. gun. So we want to keep them separate so we know number three and where it was as opposed to if we confuse with number five we've got a problem developing right off the bat. We label everything, either like with the spin case, we'll put it in a slider box.
If we put it in a bag, there's a place for the item number and a description on the bag. So basically, when it comes time to collect, this goes into. An evidence envelope goes in sideways to prevent it from sliding open and the item coming out.
And then it's folded over. So this will stay in my possession now from the crime scene back to the lab. I'll then lock it in a locker that I control, that I have the keys to. And then after I get through processing...
processing it for latent prints on the shell casing, I'll put sealing tape on it and then it'll be sealed for chain of custody and can go into the property room for storage. We don't want to introduce anything into the bag that's not already there. We basically just pop it open, take the evidence item, place it in the bag.
Fold it over twice to help prevent it from falling out during transport. Mark the bag with the evidence item number, evidence item number eight. Again, we'll put the case number, the date, all the other pertinent information on them. If there's contents to the condom, we don't want those to contaminate the outside of the condom. The reason we do a condom can link the victim with a crime and it can link the suspect to the crime.
It's one of the few evidence items that can do both at the same time. Yeah, what I'm doing is whatever's on this part of the sheet, I don't want to contaminate what's underneath the paper. Again, it's not always under field conditions, it's not possible to prevent total contamination. But we wanna make sure that we don't contaminate it any more than it has to be.
We don't use plastic bags to transport things in because plastic will hold the moisture in and will start causing certain evidence to start deteriorating or being destroyed. After all the tangible evidence is collected, the specialist collects possible DNA and other bodily fluid samples. I don't know if that's the victim's blood or the suspect's blood.
So we're gonna...we also have a bloody handprint here. Within this handprint, there could also be suspect's DNA. I didn't see blood on the victim's hand, so likelihood it's not hers. Could be her blood, but it's not her handprint.
The crime scene specialist dons two pairs of... of gloves, a set of sleeves, and a mask to guard against contamination before collecting the material. In viewing the crime scene, it appears there may be blood on the wall behind the victim. Given that the victim appears to have been bleeding, the wall could contain an important piece of evidence. This then goes into a container to protect the sample from being contaminated.
That then goes into a corner globe. The crime scene specialist will inspect other areas which might contain DNA, such as windows or door frames. Crime scene specialists spray a chemical called Blue Star on the areas of possible blood contamination.
If it glows blue, then it is swapped for DNA and sent to the serology unit. Normally if it's something we can print back at the lab, we take it back to the lab and do it. Something like this, we would lift it at the scene, put it on a print card, and then turn the print card in.
Careful not to get any air bubbles. Put your card back in. Okay.
You can rub it, you're not going to destroy the print. Pull the tape off, print comes with it. Nice.
Once everything is complete at the crime scene, specialists return to the Indianapolis Marion County Forensic Service Agency to put the sketch of the crime scene into Visio. Here, they log and seal all the evidence. They also search for latent fingerprints on evidence items.
and swab for DNA if necessary. This particular item will be swabbed by the serologist in the lab. Any firearms that have been collected will be checked for bullets to maintain safety. After every item has been logged and sealed with evidence tape, it is ready to go to the Indiana State Police Lab.
The evidence will remain under lock and key until it's transported to the laboratory.