The three officers were among the tens of thousands of men and women in blue who gathered from as far away as Canada to pay tribute last week.
The officers stopped by Pike Place Market before returning to New York. While their rental car was parked nearby, thieves broke into the 2010 Ford Explorer and ripped off all their luggage, including the uniforms they wore to the memorial.
"Two dress NYPD uniforms, one hat (with) a badge affixed to it," said Seattle police spokesperson Renee Witt.
Along with the badge, patches from other departments collected at the memorial were stolen, along with coins and business cards.
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ICE issued a statement that reads in part: "This incident may have been prevented if ICE had been notified about any of the multiple times Hernandez-Morales was released from local custody over the last few years. This is an impactful, scary example of how public safety is affected by laws or policies limiting local law enforcement agencies' ability to cooperate with ICE."