Due to an insufficient number of detectors, employees said they spent an estimated 25 minutes waiting to be searched, but the high court unanimously ruled that was not a part of their workday and therefore not subject to overtime pay.
The suit was filed by two former employees of an Integrity Staffing Solutions warehouse in the southwest US state of Nevada, where they pulled products from shelves and prepared packages to be delivered to Amazon clients.
The employees argued that daily screenings before leaving were meant to "prevent employee theft... solely for the benefit of the employers and their customers."
In a class-action suit filed in 2010, they asked for compensation under a federal law, the Fair Labor Standards Act (FLSA), for "the time that respondents spent waiting to undergo and undergoing security screenings."
They argued that time could be cut "by adding more security screeners or by staggering the termination of shifts."
An appeals court originally upheld their argument, but the Supreme Court's nine justices sided against the lower court in their first decision of this session.
"The time that respondents spent waiting to undergo and undergoing security screenings is not compensable under the FLSA," the court said in an opinion by Justice Clarence Thomas.
The court ruled that security and anti-theft measures, whether benefiting the employee or employer, were "not the principal activities the employees were employed to perform" nor were they "integral and indispensable" to the job, as required under federal law for payment.
They added that the decision was consistent with guidelines issued in 1951 from the US Department of Labor.
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