| Author | Message | ||
     Dawn Kuchnicki (Unregistered Guest) Unregistered guest Posted From: pool-72-93-58-132.bstnma.east.verizon.net |
All my vehicle windows were smashed/a brick. I saved the brick hoping to having 1 of 2 possible people pros. Police say you can not remove fingerprint from brick, Is this true? Any help? | ||
| Duncan Brown |
This suggestion is probably a bit late, but here goes! You don't comment on the surface texture of the concrete - if it is reasonably smooth, there is a product available called Magneta Flake from the K9 Scenes of Crime Equipment Ltd in the UK (fingerprints@K9scenesof crime.co.uk) which may produce results. Good luck | ||
| David Fairhurst |
Ed, Was your palmprint from the school stairs ever identified? David | ||
| Ernie Hamm |
Here is an article dealing with techniques associated with latent prints on a cement block: "Latent Fingerprint Development on a Cement Matrix", Monroe, Richard G.R., Identification Canada (Canada), 15:4 (1992) Comment: Various techniques used on cement block Ernie Hamm | ||
| Webmaster |
Concrete is generally porous, but may bear a nonporous sealant or otherwise be well polished on the (usually only one) smooth surface. Concrete indoors may preserve latent prints nearly indefinitely (like paper). I have previously developed an identifiable latent print on a concrete stairway landing outdoors (the boring details at the end of this posting are for experts*), but moisture from overnight dew or rain may obliterate impressions in many instances. Like rocks, pumpkins and other odd items, it is one of those "okay, we'll give it a try" surfaces. --Ed *Circa 1986 I had a two-year break from my three-plus decades of government employment and was selling my expertise to a Laser manufacturer in California. Although hired primarily to give training to crime labs purchasing lasers throughout the US and overseas, I also (usually weekly) processed evidence for agencies lacking lasers. Most of the cases were murders and I processed many automobiles during nights (when the assembly line was shut down) inside the manufacturing plant in Pleasanton, California. Although Los Angeles and Orange County, California had lasers, they did not have portable laser technology. I processed an entire house for an Orange County murder scene (at the time of the Nightstalker serial murders) and was asked to process the concrete exterior staircase of a school by Los Angeles City Police in a case they believed to be linked to the serial murder of “ladies of the night.” When the Los Angeles police called me and explained the details, I asked them to build a plastic tent over the staircase and superglue fume the entire area before I arrived. They did as I requested. Visual examination did not reveal any identifiable prints developed with superglue fumes or otherwise deposited in dirt or contaminates visible in “white” light. Laser exam for inherent luminescence did not reveal any identifiable latent prints. In spot-testing a small area of the concrete with Rhodamine 6G in methanol, I found that it would definitely not wash out to assist with tagging any superglue fumed friction ridge detail. As a nearly last resort, I dissolved the Rhodamine in water, producing a reddish dye solution versus the typically orange dye solution when methanol is used. The water based dye would at least wash off better than the methanol solution. The landing where the body was found was about twelve feet by twelve feet and there were perhaps ten stairs above and below it. I poured water over the entire staircase area and then washed it off with clean water so that most of the dye stain was removed. Laser exam (during the night, of course) revealed a series of gull-shaped wing patterns where the victim's buttocks had repeatedly contacted the concrete landing during the attack (rape/murder). On both sides of the area where the torso would have been, there were hand prints which luminesced from the superglue fuming/dye stain development. The hand prints were consistent with where the attacker would have placed his hands for support in the “missionary position.” I photographed the impressions (hand prints and gull-shaped buttock impressions) and also exposed 4x5 inch “close-up” negatives of one identifiable palmprint (of the two hand prints mentioned). Not being naïve and certainly suspecting that this was too good to be true, I was asked to come to police headquarters before departing Los Angeles the following morning. The LAPD suspected (reasonably) that I had planted my own palmprints when nobody was looking (after all, I was a laser manufacturer employee). After comparing the crime scene palmprint with record palmprints they took from me, they were convinced the evidence was legitimate. A few days after returning to work in northern California, the principal of the school where I had processed the staircase called me to complain. She explained that LAPD had furnished her my name and number because I was the person responsible for the red stains on the concrete sidewalk at the bottom of the staircase (I didn't wash it off, I only washed off the staircase). She explained that many of her students were remarking that the red stains were the blood of the dead woman and that her janitors were unable to rinse the stain off of (or out of) the sidewalk. I explained to her that police (including experts) normally do not clean fingerprinting powders or stains from a crime scene. Having had prior experience with the tenacity of Rhodamine dye stain, I recommended that they try sealing the concrete with lacquer and then painting over the top of the lacquer. Otherwise, the dye would certainly bleed through any paint or primer they might use to cover-up the red stains. I never heard from that school again. | ||
| Matt Lescohier |
John Q. Public here. I read previous discussions about which materials are suitable for developing fingerprints and which are not. It would seem that concrete would be a "give it a try" type surface. Realistically, what are the chances of getting fingerprints off of semi-porous concrete? Someone seems to have used a chunk of it to smash the tail light of my car... I handled the chunk of concrete once, but later reconsidered and put it in a ziploc bag. Thanks for the info. |
