CLPEX Chat Board

I'm studying for Crime Scene certification offered by the IAI and reading the Ross Gardner book "Practical Crime Scene Processing and Investigation".

From page 26 "Fingerprint examination and identification is based on both the ridge detail and the minutae present in the patterns. Ridge identification is based on at least 15 different ridge characteristics including ridge endings, bifurcations, short ridges, enclosures, ridge dot, ridge break, angular formations (deltas), overlap, spurs, bridges, trifurcations, crossings, changeovers, ridge pinch, and loops. In modern forensics the identification of a fingerprint is no longer based on an arbitrary point system (e.g., finding eight or ten similar points).

This has to be the most confusing description of fingerprint identification I've ever read!

The way the sentence reads (reader bias duely noted, hat tip Dr. Dror) is that fingerprint identification is based on ridge detail and minutae (read: point counting), but ridge identification (something completely different than fingerprint identification) is based on 15 ridge characteristics (whatever those are since 'fingerprint identification' is only based on ridge detail and minutae, but not ridge characteristics) including deltas AND trifurcations (which are like delta's ne'erdowell brother-in-law that sleeps on the couch). Even though ridge identification is based upon 15 ridge characteristics, (which could never be interpreted incorrectly as a point standard rather than an inventory of ridge characteristics) modern forensics is no longer based on an arbitrary point system (anthropometric point standard: 4 ; number of limbs needed to individualize)

While the book gets a pulitzer for using the maxium amount of adjectives to descirbe 2nd level detail (detail, minutae, characteristics and points) in one paragraph, the take away message here is that you and your hippie voodoo of including flexion and transient creases in your identifications can be damned.

----end parody----

Phooey, Boy. All yas gotta do is jus look at dem fangerprints. Eever dey matches or dey doan. Jus fergets all dem words ov 'scription and dews yer job. Dem dam signtists is gonna ruin dis bidness.

I'll pay 100 dollars to the first person that can produce notary certified court transcripts in which they use the term "Ridge Pinch"

Boyd Baumgartner wrote:I'll pay 100 dollars to the first person that can produce notary certified court transcripts in which they use the term "Ridge Pinch"

I may be testifying in the next couple of weeks... warm up your ATM!

Boyd, along with any others who may have read this, should perhaps write a review on Amazon's listing. It currently has two five star endorsements.

Some unsuspecting forensic student or wanna be may buy this and be misled by it.

Bill

ridge endings[1], bifurcations[2], short ridges[3], enclosures[4], ridge dot[5], ridge break[6], angular formations (deltas)[7], overlap[8], spurs[9], bridges[10], trifurcations[11], crossings[12], changeovers[13], ridge pinch[14], and loops[15]

That's 15 different kinds of characteristic all right.

Boyd Baumgartner wrote:I'm studying for Crime Scene certification offered by the IAI and reading the Ross Gardner book "Practical Crime Scene Processing and Investigation".

From page 26 "Fingerprint examination and identification is based on both the ridge detail and the minutae present in the patterns.

The first thing that popped into my head was the scene from The Blues Brothers where the woman at Bob's County Bunker tells the boys they have "both kinds of music - Country and Western."


Scary thing is they do indeed take the questions from the stated texts. I have no idea if they use that section today. I took mine before the tests were updated (so I'm not really giving anything away here), and it had been a LONG time since it was updated. But I had no idea just how long it had been, and you know how your mind sort of filters out stuff you don't pay much attention to any more. But it was sure there in the texts. So I hit a bunch of questions on bodily fluid identification from "olden days" and had to drag up some very stale memories. All my stuff on alleles and such was useless. There was one DNA question, and that was "What does DNA stand for?" (I think I got that one right.)

From page 238

"In the lab, the fumed print can be dyed using rhodamine 6G, Androx, or basic yellow dyes..."

Androx?!?!?! Really? I'm all for pioneering and research, but I'll wait for the validation study before using a libido enhancer to enhance CA.

http://www.calcompnutrition.com/androx.html

And no Steve, I didn't know what Androx was before I googled it this morning.

Boyd Baumgartner wrote:Someone wanna 'splain this to me . . .

Okay, Boyd, I know you love your job, BUT . . . . . . . . . . . . .

Boyd Baumgartner wrote:

From page 238

"In the lab, the fumed print can be dyed using rhodamine 6G, Androx, or basic yellow dyes..."

Androx?!?!?! Really? I'm all for pioneering and research, but I'll wait for the validation study before using a libido enhancer to enhance CA.

http://www.calcompnutrition.com/androx.html

And no Steve, I didn't know what Androx was before I googled it this morning.

I don't know about androx, but we have been using ardrox for more than 10 years now.

Gerrit

Pat, with Androx I'm able to love more than just my job!

*note: this is not a paid endorsement

I'm not sure what he was trying to say with "ridge pinch" but I sometimes refer to ridge spacing as the PITCH of the pattern as in the pitch of a thread or number of threads per inch.

I'm sooo frightfully embarassed! I won't be able to use the term "ridge pinch" as I'm not sure what it is. Could someone please tell me?

While I can't say as I have ever heard the term "Ridge Pinch", I would take a stab at thinking it refers to when a ridge of a certain thickness gets thinner in a spot and then thickens back up - it gets "pinched". I just testified the other day and if I had read about that $100 offer, I think I might have somehow worked a "Ridge Pinch" into the desription of Levels of Detail and beaten Steve to the punch/pinch.