Superglue Oddities

[Charles Parker]

The Case of Black Ridges and Not White!

This case occurred in the early 80’s when superglue fuming first started. The case was a Kidnapping and Sexual Assault. The victim had been taken from a local Stop and Rob and forced to a motel when the victim was assaulted. As the suspect was leaving he tossed the room key on a table. The key was the older type with a large black triangle key fob that you used to see motel keys on (if anyone can remember that far back). We had just obtained our first aquarium (cracked that would not hold water and someone did not want anymore), and had actually fumed another piece of evidence in a drug case a few days earlier. So this was my second case involving superglue fuming. When the key fob was removed latent prints could be easily seen. It was photographed with a 4X5 Graflex camera using Technical Pan Film but the pictures were strange. When a suspect was developed the comparison was started it was determined quickly that we were comparing black ridges with black ridges and not the expected white. Upon looking at the key fob it had a coat of material on it and when the subject touched it the material was removed. It was a classic take away print with the glue reacting to the surface of the plastic and with the black underneath we had ridge detail black with white furrows.

The Case of Fuzzy but Reversed

A few years later we were packing drug evidence into glue tanks and gluing everything in sight. We begin to notice that some of the prints were looking a little fuzzy and when we observed those fuzzy prints we could generally find the mirror image on some other item. Soon we learned about lateral transferred latent prints and learned quickly not to pack items so close together in the glue tanks. Lateral reverses do occur and has been documented in several articles over the years.

The Case of Sharp but Reversed

A few years ago when teaching a class on Techniques of Developing Latent Prints I had a student approached me and ask why did the Superglue develop latent prints on both sides of the plastic. I said because you touched both sides and he denies that he did. I then said you got it too close to someone else’s and it was a lateral transfer. He said there was not anything else close to it and the print on the other side was EXACTLY OPPOSITE and a REVERSAL of each other. I said “yea right” and asked to see it. He produced it and sure enough it is the exact same print exactly opposite sides of the small piece of plastic. The plastic is gray and very thin, probably about 2 mil where you can shine light though it. I call it the reversal by osmosis. I have yet to reproduce this phenomenon.

The Case of the Slipping Ridges

This is not my case but was sent to me. A piece of aluminum foil was processed with superglue and then the prints on the foil were treated with Rhodium 6G and several ridges on each latent print just slipped away from the surface. You can see them as they are like pieces of spaghetti hanging down from the prints and the ridges are intact but just not part of the latent anymore. I have shown this one to a number of people and 3 have told me that they have had a similar occurrence with Rhodium 6G.


The Case of Superglue Trees

This is not my case but I was made aware of it. Apparently some items were processed with superglue and the glue polymerized out from the surface into what I would call a number of small stalks with branches on the end. It looks like a little forest growing out of the surface of the item. This has been attributed to either static electricity or spore growth. I have not had this occurred in any of my processing and only saw the picture of it recently. Pretty but weird.



Perhaps you have an unusual CAE (Superglue) Story you would like to share.

[Gerald Clough]

The Case of Sharp but Reversed

A few years ago when teaching a class on Techniques of Developing Latent Prints I had a student approached me and ask why did the Superglue develop latent prints on both sides of the plastic. I said because you touched both sides and he denies that he did. I then said you got it too close to someone else’s and it was a lateral transfer. He said there was not anything else close to it and the print on the other side was EXACTLY OPPOSITE and a REVERSAL of each other. I said “yea right” and asked to see it. He produced it and sure enough it is the exact same print exactly opposite sides of the small piece of plastic. The plastic is gray and very thin, probably about 2 mil where you can shine light though it. I call it the reversal by osmosis. I have yet to reproduce this phenomenon.

One possible explanation is demonstrated in this study of the effectiveness of gloves in avoiding adding ridge impressions to the crime scene:

http://www.crime-scene-investigator.net ... Scene.html

I don't have material specs on standard Oak Handies, but from the catalog photo, they could be even more then 2 mil, and 2 mil is more like food service gloves:



In the study, they were leaving readable ridges by transfer of media from ridges impressed through the vinyl glove, so I would assume the glove itself would have had a reversed pattern in picked up media, had it been processed, and the same phenomenon could have shown up on the teaching sample. Not quite osmosis, but certainly effected through the barrier.

[Charles Parker]

Gerald, you have given me something to try. It could be that when he pressed his finger on the plastic the surface opposite was contaminated and like a glove picked it up.

I can think of several reasons why it would fail to duplilcate the one I have but I do not have a lot of confidence in the failure descriptions so I will try to that to duplicate.

Others have attributed it to the person being diabetic and his sweat being more like acetone than water. Others have attributed it to static electricity since he placed the plastic right over the Sodium Hydroxide pad and the smoke was traveling up both sides of the plastic.

One previous student has told me she has duplicated it, but she wants to try several more times before she collects the bet from me.