Forensic toxicologist Dan Berkabile was again called as a witness and testified for nearly 30 minutes on issues such as beating a urinalysis test. He said it can be done by ingesting substances to dilute the presence of illegal drugs or by inserting items into the actual sample before it's tested.
"There's a certain percentage of sophistication out there that can beat the test," Berkabile said. "There are things out there that will help (people) beat a test. I myself could beat a urine test.
"It takes about a microliter, which I equate to about a fifth of a drop, to alter a test. Even if a person is testing in front of someone, all it would take would be something under a fingernail to alter the test or something else ingested an hour or so before being tested.
"Five percent (who beat drug tests) is a liberal estimate; three percent would be more accurate."
Berkabile admitted, however, that someone who tests hundreds of times, like Valenzuela must under the terms of his conditional license, would have a hard time consistently beating the test and would more than likely eventually be caught. Since signing his conditional license in 2001, Valenzuela has yet to produce a positive urinalysis for drugs.Other testimony pertained to Valenzuela's shaving practices. Those witnesses were jockeys Danny Sorenson and Tyler Baze, David Stark, the jockeys' room masseur, and CHRB investigator Mike Kilpak.