Best Practice Proced

for The Exchange 

Latent Identificat

Services

The Texas Experience
Addressing the Needs o

Texas Latent User

Latent exchange must:

 Be Inexpensive Be Easy to Use Be Vendor independent WORK!

Evaluation of solutions in Texas poideployment of Universal Latent Woand a Texas DPS hosted Store & Fodevice.
Factors In Decision

Inexpensive 

 Costs to latent user are limited to PC, 1000 ppi 

license and internet connectivity costs. ULW so

 Costs to host include mail server and (if neede

AFIS system.

Easy to use

 ULW software is intuitive and easy to learn Exchanging latents is as simple as using email

Vendor Independent

 Type 9 Record provides AFIS vendor with vend

set

 Use of standard FBI EFTS TOTs (LFFS / SRL)

It works

 Texas users have made many hits against IAFI

NEC AFIS utilizing ULW and Type 9 records.
The Texas Implementa

Outbound Latent Exchange - Universal Latent Workstation (ULW) to 

AFIS

Inbound 

– ULW to Texas DPS AFIS (Inbound)
ULW Outbound

FW-L 

DPS

S & F

INT RANET / INTER

NEC FW-L (with installed ULW) 

generated LFFS transaction or stand alone ULWLFFS transaction is forwarded to Store 

and Forward deviceS&F mails the LFFS to the FBI’s IAFIS via the CJIS WANLFFS transaction is processed and returned to the contributor as an SRL or ERRL using the same path.DPS will be able to route transactions to other AFIS systems as they are able to accept Type 9 submissions.

Harris County 

(Houston, Tx)
ULW 

Inbound

Major difference between inbound and outbound concerns the need to manipulate images maintained in AFIS to insure compliance with national standards.For Texas, images stored in the NEC AFIS are modified by adding the 18 extra bytes of data necessary to distinguish the image as a NIST Type 4 record.

ULW

ULW

ULW

ULW
Many AFIS sys

fingerprint ima4 format. Whproprietary imare optimized native systemsa readily exchModifications mthese images them in dissim
Logical record length (LEN)

This mandatory four-byte binary field shall occupy bytes one through four. It specifying the total number of bytes, including every byte of all nine fields co

Image designation character (IDC)This mandatory one-byte binary field shall occupy the fifth byte of a Type-4 reco

contained in this record. The IDC contained in this field shall be a binary represe(CNT) field of the Type-1 record.

Impression type (IMP)This mandatory one-byte binary field shall occupy the sixth byte of a Type-4 recodescribing the manner by which the fingerprint image information was obtained, Finger position (FGP) - This mandatory fixed-length field of 6 binary bytes shall 

positions of a Type-4 record. It shall contain possible finger positions beginning i

of the record). The decimal code number for the known or most probable finger pentered as a binary number right justified and left zero filled within the eight-bit b

Image scanning resolution (ISR)This mandatory one-byte binary field shall occupy the thirteenth byte of a Typeif0le if the minimum scanning resolution is used, and a in1l, if the native scanniHorizontal line length (HLL)This mandatory two-byte binary field shall occupy the fourteenth and fifteenth bspecify the number of pixels contained on a single horizontal line of the transmVertical line length (VLL)This mandatory two-byte binary field shall occupy the sixteenth and seventeentto specify the number of horizontal lines contained in the transmitted image.

Grayscale compression algorithm (GCA) - This mandatory one-byte binary fie

Type-4 record. It shall be used to specify the type of grayscale compression algono compression. Otherwise, the contents of this byte shall be a binary represent

particular compression technique used by the interchange parties. The domain r

these numbers to the compression algorithms.

Additional Consideratio

Security

 Authentication Encryption 

S&F Functionality

 Logging Job Cueing

IIETF Best Practices Document
Questions?

Mike Lesko

Texas Department of Publi

mike.lesko@txdps.state.

(512) 424-2524