Expert testimony admitted after probative value outweighs the danger of prejudice

Expert witness testimony needs to be formed on the basis of a scientific, technical or other specialized knowledge and not on mere speculation or belief of an expert. If the opinion satisfies this first criterion, it is usually put to test on another aspect – whether its probative value could be outweighed by a potential unfair prejudice. If there is a substantial chance of deluding the jury, the testimony could still be rejected in spite of being scientifically sound and reliable. In a recent case, the Fourth Circuit discussed the issue.

MARPOL, an international treaty formulated with the objective of preventing water pollution from ships has laid down regulations pertaining to ocean-going vessels. One such regulation considers as an unlawful activity the failure of the officer(s) in charge of a vessel in carrying out proper treatment of the bilge water, before discharging it in the ocean and in maintaining a proper Oil Record Book, containing details of how such bilge water is disposed.

In U.S.A. v. Lambros Katsipis, there was an allegation against the Chief Engineer, Lambros Katsipis, of an Ocean going cargo called M/V Antonis G. Pappadakis (the “Pappadakis”) of violating 33 U.S.C. § 1908(a) (2012). His crew members alleged that Katsipis had not been filtering the bilge water through the Oily Water Separator of the ship as was required by MARPOL and was instead passing the cleaning water from the fuel tanks through the Marine Sanitation Device before releasing it into the sea.

Kristy Juaire, a chemist at the Coast Guard’s Marine Safety Laboratory, was summoned as a chemical expert witness to present her findings on the above allegation. She carried out chromatography and mass spectrometry tests on the Pappadakis vessel, which revealed that traces of fuel oil, lubricating oil, or petroleum oil was indeed present in the Marine Sanitation Device’s sewage tank.

She said that this should ideally not have happened if the bilge water was not being run through the Marine Sanitation Device and was processed through the Oily Water Separator. She added that the above hydrocarbon finger print obtained from Marine Sanitation Device was not the same as samples taken from elsewhere on the Pappadakis. But she cautioned the court against absolutely relying on her findings to hold Katsipis liable for running the bilge water unlawfully through the Marine Sanitation Device. According to Juaire, there was always the chance of finding different hydrocarbon fingerprints at different locations of the vessel, when the ship was subjected to continuous mixing and weathering over time.

There was also a summary report prepared by Lieutenant Junior Grade Crystal Tucker who checked the Oil Record book for the last twenty three months and found that the Oily Water Separator was only run seven times when pappadakis was under Katsipis’ control as against sixteen times when his predecessor was in charge. The latter had processed 325 cubic meters of bilge water instead of 25 cubic meters as was done by the former over the same period of time (eleven and a half months).

The United States District Court for the Eastern District of Virginia accepted Juaire’s testimony and found Katsipis guilty of violating 33 U.S.C. § 1908(a) (2012) and sentenced him to one year’s probation, including four months of community confinement.

Katsipis bought an appeal against the alleged abuse of discretionary power by the District Court. On appeal the Fourth Circuit did not accept the contention of the appellant and held that as long as an expert opinion is based on scientific, technical or other specialized knowledge and not on the mere speculation of the concerned expert it should be accepted by a court.

The court also recognized an exception to this rule and opined that where the chances of causing unfair prejudice from accepting such expert opinion trumped the probative value of the testimony, the courts could discard the expert testimony.

Applying the above rule the Appellate Court did not find any issue of unfair prejudice being caused to the appellant by accepting the testimony of the expert, especially since her statement was also corroborated with the summary report of the Oil Record Book prepared by Tucker and the allegation of the crew members of the vessel. Accordingly the Fourth Circuit upheld the admission of the expert testimony of Kristy Juaire and affirmed the ruling of the District Court.