Chemist in the Courtroom

Tales from the witness box

Chemistry Communications Ethics

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September-October 1999

Volume 87, Number 5
Page 390

DOI: 10.1511/1999.36.390

The two workers had been spray-painting the interior of a ship compartment—a small, unlit, unventilated and windowless room. As they began to walk out of the room after finishing the job, a flash fire ignited. With solvent fumes trapped next to their skin by coveralls, they suffered burns over more than 80 percent of their bodies.

What happened? This question soon became a legal one as the injured workers sued their employer, the paint company and several other parties. Was the paint defective? Had the operators of the ship-repair facility followed safety regulations and procedures?

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As a consulting chemist specializing in coatings, I've been asked to investigate many cases where scientific evidence can be crucial in determining who is at fault. People have become used to seeing a scientist in the witness box, especially now that DNA evidence is common in criminal cases. But what's remarkable is how many other roles scientists play in the legal process. In 17 years as a "forensic chemist" I've appeared in court just five times. Many more times I've simply investigated the circumstances of a case with a scientist's eye, taught a bit of science outside the courtroom to a lawyer or a judge, or helped participants understand during the initial discovery process how certain hypotheses—and therefore certain claims—could be excluded as inconsistent with evidence.

Consider the case of the burned shipyard workers, one of whom unfortunately died. Photographs taken by a state inspector showed a trouble light (an incandescent bulb on an extension cord) in the room, a clear fire hazard. And the inspectors' interviews revealed that welders had been working on the outer plates of the ship room while the painting was under way. As a scientist I could conclude that the label warnings on the paint were appropriate, so that the paint was safe under normal conditions; however, the trouble light and welding each provided potential sources of fire initiation. These judgments on my part became factors in the settlement.

Typically, a case in my field deals with the failure of a coating, a safety question related to the coating or the alleged theft of a coating; typically, the chemist is called in by a paint company; and typically, the case ends in a settlement. In most cases I haven't known at the outset what role I would play—beyond, perhaps, preparing an analysis and report.

Legal action was threatened, for instance, against a contractor who had subcontracted some painters to apply a dark-brown latex paint on window and door frames after construction was complete on some condominiums whose exterior was unpigmented stucco. Brown paint streaks appeared on the stucco, and the contractor couldn't wash them off.

I knew just enough about San Francisco weather and latex paint to figure out that if the painters stopped work just before dusk each evening (as they said they did), the paint they applied might have been diluted by the condensing evening fog that comes through the Golden Gate, draining pigment from the painted surface onto the stucco. Still, the homeowners needed a remedy. I bought a small low-pressure sand blaster and a bag of talc and showed them how blasting the surface with a soft mineral would clean the stucco without scraping it. I was to give no star performance in the witness box in this case; instead I managed to stop a lawsuit and provide a practical remedy.

Scientist-Detective and Scientist-Teacher

When a lawsuit cannot be so quickly resolved, the expert may serve by instructing a lawyer in the case about the science involved—giving advice, primarily, on whether the scientific advice the lawyer wishes to present has merit. Sometimes getting to the science in the case takes a great deal of investigation.

I once found myself involved in a case in San Jose, California, where a fire had destroyed an apartment house, and the local natural-gas company was being blamed. It was alleged that a rubber diaphragm in a valve controlling the gas supply to the house had failed. I supplied engineers with tensile-test equipment and helped with strength testing. Valves of the type in question failed only at extreme high pressures and did so leaving ragged tears in the diaphragm. The suspect diaphragm did not perform differently on any of the engineers' strength tests.

But on a visit to their offices a week before my deposition, I looked again at the hundred-plus photographs from the stress tests and spotted three that seemed different. Instead of ragged tears, they showed sharp cuts—probably, I surmised, a razor cut partway through the fabric that had happened when the fabric was laminated or die-cut. Razor slices are notoriously hard to see unless you stretch the substrate, and so it would be unlikely that these would be detected during assembly of the valves.

The engineers blew up the photos 20 times, exposing the damage to the fibers and evidence of the age of the cut. At the deposition eight lawyers posed questions for 10 to 12 hours; in the end the photographic evidence of the razor cuts was definitive, and the case was settled for a fraction of the amount sought.

But a lot of the work of a scientist involved in the legal process is pure education. As a coating chemist I often rely on kitchen analogies to describe polymeric or colloidal systems, relating a polymer to a plate of spaghetti, a monomer to a plate of macaroni and colloidal systems to milk, pudding, gelatin and gravy. This sort of background understanding is important to an attorney preparing for a courtroom apppearance, who must frame a set of questions to ask in the courtroom so the judge (and jury, if needed) can get the same training painlessly, but thoroughly enough to be able to make decisions about the importance to the case argument.

Scientists Have 'Big Cases,' Too

On one case I was involved from beginning to end: a lawsuit involving the alleged theft of a trade secret. The technical director for a paint company called one day to ask if I could help interpret some infrared spectra (used in quantitative analysis of organic formulations).

I went to visit him, and he introduced me to the company's lawyer, a rather famous Los Angeles attorney. The lawyer and I worked together for about 10 months. I had to deal with so much paperwork (cubic yards of it) that I hired my mother-in-law (a retired Clerk of Courts) to help sort, file and enter into the computer information involved in the case.

The suit alleged that a person back East had illegally obtained the formulation for a valuable unique paint formulation. In the paper search, we found a copy of the actual stolen batch card. However, a key component of the formulation was not listed on the card, as the amount used needed to be adjusted for each batch.

The impostor paint, which turned up in Boston, looked like the L.A. paint when applied but did not have the long life or maintenance advantage of the original. Even so, it was making a ton of money for the recipe thief.

The formulation was unique. There were five essential ingredients, and their proportions were critical. That the Boston firm's recipe matched in all five components to the third significant figure was a smoking gun.

One of my assignments was to get spectroscopic comparisons of all competing products. I was surprised to find that one company's formulation matched the infrared spectrum of the L.A. formulation but had completely different components (except one) and did not quite have the physical property performance the L.A. product had. One can imagine their chemists trying formulations until they got an IR match and thinking they had it. Until I saw those two spectra, I'd have bet any amount that no two different paint formulations would have the same spectra. So much for science.

In many cases, the trial is the anticlimax for the expert, and the handling of expert testimony can sometimes surprise the logical scientist. In this case, probability predicted that our client's formulation could not be reproduced to the third significant figure by chance but once in 1015 times—several billion times less likely than winning the California lottery. The judge would not allow that argument, as there is a California Supreme Court ruling prohibiting statistically based predictions as evidence! Nevertheless he immediately found for our side, and my client ended up owning two more companies.

Overall, I'm impressed by the potential for scientists to perform service in disputes and the amount a scientist can learn from involvement in these cases. The consulting scientist can find remunerative employment as an expert for the law, in preparation for and in the courtroom—and be entertained in the process.

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