EAGAN, Minn. (FOX 9) - Eagan Police investigators are using infrared camera technology together with different lighting sources to help them find evidence invisible to the human eye.
The camera is made specifically for forensic investigation. By using different lenses, filters and external light sources, investigators are able to see things they can’t see with the naked eye.
One of the applications for the technology is to find bruising under a person’s skin. According to Detective Karin Pederson, bruising that is not visible to the naked eye could be visible under the infrared light camera for as long as a few weeks.
“[In a] domestic assault with a strangulation, we might not be able to see the bruising right away; we can wait a couple days and see even more enhanced bruising that we weren’t able to see,” Pederson said.
Detective Pederson says the technology is also useful for presenting a case to a jury in court. She says normal cameras can have a difficult time capturing coloring from bruising or other marks on the skin. The infrared camera allows investigators to give prosecutors clearer evidence that might help a jury better understand the severity of an injury.
“It’s another step of giving evidence, show the jury what we’re able to see, what happened, paint a picture for the jury and hopefully help our victims out to get a conviction against their abuser,” Detective Pederson said.
The infrared camera is also useful in helping investigators identify different types of ink. Under the camera and a U-V light, different inks give off different glows. With this technology investigators can see if a check or document has been altered.
Another use for the infrared camera is finding blood and bodily fluids on surfaces where it could be difficult to see, for example, a black piece of clothing. By using the infrared light, investigators can find blood stains without having to potentially tamper evidence with chemicals.
Officials with the Eagan Police Department say the infrared technology they are using has been around and used by other law enforcement agencies across the country for about three or four years.