Scientific method turns crime fighter

August 26, 2007|By Melissa Harris | Melissa Harris,Sun reporter

Police chemist Joshua Yohannan crushed the pink Ecstasy tablet with a mortar and pestle, dripped a solution of sulfuric acid and formaldehyde into a plastic tray, and then sprinkled the pink powder on top of it.

Yohannan expected the mixture to turn purple and then black. He hoped that a few granules would turn orange. And that is what happened.

The triple-color change meant that the pill with the bunny logo contained MDMA, or Ecstasy, and methamphetamine, a far more dangerous and addictive drug. The results of the test could lead to stiffer charges against the Columbia defendant who had the tablet and other drugs in his house.

For more than a year, Howard County police have employed Yohannan as their drug chemist. He works on Howard County cases at the new state police Forensic Science Laboratory in Pikesville.

He handles about 20 drug seizures a week and testifies in court if the cases go to trial. His hiring has meant quicker drug identifications, tougher charges and fewer court delays, said Lt. Keith Lessner, commander of the county's vice and narcotics unit.

Before Yohannan's arrival, a state chemist would analyze drugs and testify in Howard County cases, but those chemists also would handle seizures from other counties. If two cases were scheduled for trial the same day, the chemist would attend the one that was booked first, Yohannan said.

A judge would delay the other case or toss it out when the chemist did not arrive.

"In the past, [acquittals or delays] have happened plenty of times -- more likely than not," Lessner said.

The job requires Yohannan to follow strict protocols to avoid evidence contamination. He wears a lab coat, snaps on latex gloves and slips on protective eyewear.

All evidence bags are heat-sealed. Yohannan checks to make sure the serial numbers on the bags match the inventory description. He also jots down a description of the contents. The length of each bag is measured to ensure it hasn't been cut and resealed.

Yohannan cuts open the bag with scissors at his desk in the lab and then analyzes each drug one at a time. A recent seizure included the pink "bunny" Ecstasy tablet, two marijuana buds and a small bag of cocaine.

Marijuana is relatively easy to identify because there are very few plants that are both green and brown, he said. When he places the plant under the stereomicroscope, tiny hairs and shiny, gold globules of resin appear.

To confirm his conclusion, Yohannan puts a piece of the marijuana in a test tube and shoots three chemicals into it. Two layers form. Yohannan presses the tube against a "vortex mixer" to blend the liquids.

Once the chemicals settle, the two layers reform. One is light purple, the other a dark purple.

"Nothing else can create this result but marijuana," he said.

More complex substances, such as cocaine and Ecstasy, require computer analysis to confirm an initial finding. To figure out what is inside a tablet of Ecstasy, a small amount of the substance is heated in an oven that looks like a large computer printer.

The heat splits the molecules and converts them into gases.

The gases then float through the instrument at different speeds. The larger the molecule, the longer it takes to reach the finish line -- where the computer measures the molecule's weight and shape and identifies it.

The pink tablet with the bunny imprint, which Yohannan tested last week, contained MDMA, methamphetamine and procaine, commonly called novocaine.

"When he sees something unusual, he's going to give us a call," Lessner said. "And he's able to update us on the quality of the drugs, particularly cocaine, so we can get a sign of where we're at on the food chain."

Yohannan, who lives in Frederick, grew up in Rutledge, Pa., and graduated from Vassar College with a degree in chemistry. He met his wife at graduate school orientation at North Carolina State University, where they both majored in chemistry.

"My wife got me into this," he said.

After graduating in 2003, Yohannan's wife took a job with the state police, and he got a job with Baltimore's crime laboratory.

"I grew up in a small town in Pennsylvania where there was one shooting in 15 years," he said. "The night before I started [in Baltimore], a guy beheaded three little kids, and I was sent to analyze the suspect's house the next day."

He moved to Baltimore's drug analysis team of 20 chemists and then learned about Howard County's opening at the state police laboratory. Yohannan's wife worked at the lab until she recently took a job with the federal government.

Yohannan said he loves his work, but that repeating the same tests can become monotonous.

"When I get a bunch of marijuana cases in a row, it can be very slow," Yohannan said. "And in the wintertime, drug seizures slow down because everyone's inside and it's harder to find people."

To keep the job interesting, he is building an inventory of Ecstasy pills, which he keeps locked in a wooden cabinet in the laboratory. He hopes to publish an analysis of the pills' contents and manufacturing trends in a scientific journal.

His discovery of glitter in one pill, believed to be a marketing tactic, resulted in a mention in Microgram, the U.S. Drug Enforcement Administration's newsletter.

"I want to show that there's so many other things being put in these tablets that are not harmless," he said.

melissa.harris@baltsun.com

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