AP investigative reporters Garance Burke, San Francisco, and Jason Dearen, New York, worked their sources and turned a tip into an exclusive story detailing how Vice President Mike Pence ordered the U.S. Centers for Disease Control and Prevention to use the pandemic as justification to halt immigration into the U.S., over the objections of the agency's scientists who twice refused to take the action.

The investigation started with a tip to Burke, when a source told her that the CDC had been pressured to go along with a White House order to shut the borders to immigrants and asylum seekers by invoking powers only afforded the agency during a pandemic. Burke’s source said that the order was issued despite CDC scientists’ assertion that there was no good public health reason to do it.

Burke notified Dearen, who started working CDC sources. After a couple of fruitless weeks, Dearen succeeded in identifying a person close to the events who agreed to talk. Dearen also spoke to a former top aide to Pence who confirmed the story, on the record, and who revealed that Stephen Miller, a top aide to President Donald Trump, had been pushing the move behind the scenes for weeks.

Meanwhile Burke moved the story beyond politics to bring home the order’s human toll, just days before the vice presidential debate. She gathered data that showed nearly 150,000 people, including 8,800 migrant children, already had been expelled under the order, and she interviewed the father of a 16-year-old Honduran boy who had been held in government custody under the order, not allowed to see anyone until the American Civil Liberties Union filed suit.

Even on a weekend dominated by news of Trump’s hospitalization due to his COVID-19 diagnosis, the piece was the top AP News story with more than 1.5 million views and retweeted thousands of times in English and Spanish. The story was widely used and cited by local and national news outlets.