Manhattan District Attorney Alvin Bragg has had a historic year, from the first indictment of a former United States President to joining the battle against ghost guns.

The one-time head of security for former mayor Bill de Blasio pleaded guilty in Manhattan on Wednesday to deleting text messages and refusing to give investigators his cellphone during a probe into Mr. de Blasio’s misuse of city funds.

Howard Redmond, who as an NYPD inspector oversaw Bill de Blasio and his family’s around-the-clock security the whole time the former New York City mayor was in office, pleaded guilty to felony charges stemming from his work for City Hall moments after they were unsealed in court Wednesday.

The NYPD inspector who oversaw former Mayor Bill de Blasio’s security detail pleaded guilty in Manhattan Criminal Court on Wednesday afternoon to six charges related to his attempts to obstruct an investigation into de Blasio’s alleged misuse of the detail.