Aerial Photography Expert’s Testimony Considered Admissible For Relying On Various Methodologies


Photography Expert

Court: United States District Court for the District of Arizona
Jurisdiction: Federal
Case Name: El Paso Natural Gas Co. LLC v. United States
Citation: 2019 U.S. Dist. LEXIS 26054


The plaintiff El Paso Natural Gas Company, LLC brought claims against the defendants, the United States of America, the Department of the Interior, the Bureau of Indian Affairs, the U.S. Geological Survey, the Department of Energy, and the Nuclear Regulatory Commission (collectively, the United States) under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA). El Paso sought to recover response costs incurred in remediating 19 historical uranium mines located on the Navajo Reservation Mine Sites. The United States asserted that El Paso was responsible for all response costs and moved to exclude opinions of El Paso’s aerial photography expert.

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The Plaintiff’s Aerial Photography Expert

The expert’s resume reflected a 40-year career in natural resource exploration, mine development, mine operations, environmental permitting, and mine reclamation. However, it appeared he did not specialize in aerial photography analysis. The expert testified to learning about aerial photography analysis in several courses focused on other subjects, and some fieldwork, at the Colorado School of Mines. The expert also testifies that his firm engaged in aerial photography analysis for clients. El Paso provided no other information about his experience in this field. The United States thus argued that the expert lacked the requisite knowledge, skill, experience, training, or education to render opinions based on aerial photographs.

In his expert report, the expert opined that the United States Atomic Energy Commission (AEC) conducted exploratory drilling at all of the Mine Sites with the possible exception of Ramco 20, 21, 22, and 24. During his deposition, the expert clarified that he could not say with reasonable certainty that the AEC drilled at some Mine Sites, merely that it was possible. The expert’s deposition suggested that he confirmed information from aerial photographs by field investigations on the ground. The United States argued that the expert’s report contained a February 1954 aerial photograph with added annotations of features that he observed on much later photographs or after visiting the mine sites in 2015 and 2016.

The United States argued that this photograph was unhelpful to the factfinder and created a false impression that the annotated features were present in 1954 when, in fact, there was an insufficient basis to determine precisely when these mining activities and disturbances occurred. The United States did not explain how the use of an allegedly inaccurate exhibit disqualified an expert from testifying under Rule 702. In response to these criticisms, the expert testified that he used the annotated 1954 image to display information from his findings throughout the study, not to attribute that information to 1954. In his rebuttal report, the expert reiterated that he did not intend for the annotations to show that drill trails were present in 1954.

Court’s Discussion

The court couldn’t conclude that coverage of aerial photography in several college classes and fieldwork, and his firm’s aerial photography analysis provided sufficient basis for the court to conclude that he was qualified to provide expert opinions in this field. But the court couldn’t tell whether such qualifications were key to his opinions. If the expert’s opinions were based on features confirmed on the ground, and not solely on aerial photographs, then his resume suggested that he likely had sufficient expertise to provide the opinions. The court decided it must resolve this issue on the basis of the foundation of and opinions expressed during the bench trial.

The United States argued that the methods the expert used to interpret aerial photographs were not reliable. The United States contended that the expert did not obtain aerial photographs of sufficient quality, prepare orthomosaic photos, or view the photos stereoscopically using techniques that would allow him to appreciate the depth and view the aerial photographs in 3D.

The United States  further argued that the expert’s conclusion that the AEC conducted exploratory drilling at 19 Mine Sites was not supported by the facts or confirmed to a “reasonable degree of scientific certainty,” and called for the exclusion of the expert’s testimony on the basis that he identified only a possibility, not a probability.


The motion to exclude the testimony of the plaintiff’s aerial photography expert was denied without prejudice.

The court held that the plaintiff’s expert appeared to have relied on more than aerial photographs to support his conclusions. The court held that El Paso had presented sufficient evidence of other methods for interpreting aerial photographs besides stereoscopic viewing. The court therefore concluded that the expert’s methods were sufficiently reliable for his opinions to be admissible. The plaintiff expert’s testimony that El Paso’s predecessors likely did not perform certain site activities — regardless of who else might have performed them — was relevant to equitable allocation issues.

The court also held that to the extent the United States objected to the admission of the exhibit under Rule 403, it could make the objection at trial.

What We Can Learn From This Case

Expert testimony need not be sufficient to support the verdict before it is admissible. Reliable expert testimony need only be relevant, and need not establish every element that the plaintiff must prove in order to be admissible.