How missing Secret Service text messages became a political scandal

It's still unclear whether the Secret Service received the guidance.
A source familiar with the investigation told CNN the Secret Service tried to find it last week but could not.
The internal Secret Service notice made clear that employees were solely responsible for saving records that had to be preserved by law.
DHS Inspector General Joseph CuffariFebruary 26, 2021: DHS Inspector General Joseph Cuffari requests electronic communications from the Secret Service for the first time, according to agency spokesman Anthony Guglielmi.
Among the agencies to receive a letter is the Department of Homeland Security, which oversees the Secret Service.
May 2021: The Secret Service notifies the DHS inspector general of missing text messages related to the phone data migration issue, according to sources.
June 11, 2021: The DHS inspector general requests text messages "sent or received by 24 Secret Service personnel during the period of December 7, 2020 through January 8, 2021."
That message was from former US Capitol Police Chief Steven Sund to former Secret Service Uniformed Division Chief Thomas Sullivan requesting assistance on January 6.
December 2021: The DHS inspector general reopens his inquiry into the Secret Service text messages.
February 2022: The Secret Service notifies the DHS inspector general a third time of the data migration issue, according to a DHS source.
July 15, 2022: The inspector general's office The inspector general's office briefs the House select committee on the Secret Service texts.
July 19, 2022: The Secret Service The Secret Service responds to the House select committee by providing thousands of records.