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 inspector led the New York Police Department’s Executive Protection Unit, which provides security for the mayor, had tried to keep the device from the Department of Investigation during the probe.

Mr. Redmond, 58, pleaded guilty to two counts of tampering with physical evidence, a felony. He also pleaded guilty to two counts of official misconduct and two counts of obstructing governmental administration.

The charges stem from the city Department of Investigation probe into how Mr. de Blasio had used his mayoral security detail for political and personal purposes, including in 2019 when members of the detail accompanied him on the presidential campaign trail.

Those trips cost the city nearly $320,000, according to a report released by the Investigation Department in October 2021.

This is a breaking story and will be updated.