Minneapolis police Chief Medaria Arradondo has named a new assistant chief to replace his retiring No. 2, as part of a larger shake-up of the department's command staff.

Deputy chief Henry Halvorson will step into the assistant chief role of the departing Mike Kjos, who plans to retire in January.

In his new post, Halvorson will effectively take over the department's day-to-day operations, overseeing its three specialized divisions: investigations, patrol and professional standards.

After joining the MPD in 1992, Halvorson worked his way up the promotional ladder as a sex-crimes detective, field supervisor and lieutenant in charge of Internal Affairs, where he also spent time as an investigator. He's spent the past three years as the deputy chief in charge of the professional standards unit. He is the department's second-highest ranked American Indian in the department's 150-plus year history — after former chief Janeé Harteau — and the first Native man ever to hold that rank.

In the latest shake-up of his command staff, Arradondo also promoted Amelia Huffman to become one of the MPD's three deputy chief positions. She will fill the vacancy left by Halvorson as the head of the professional standards unit.

The moves come at a time of upheaval for the state's largest police agency, which is under a human rights investigation while facing a wave of officer departures, rising crime and ongoing calls for its defunding and even disbandment. The changes will go into effect in the coming weeks.

The outgoing assistant chief, Kjos, who came into the job during another turbulent period — the aftermath of the fatal police shooting of Justine Damond Ruszczyk — oversaw a dramatic shift in how the department pursues stolen vehicles and helped shepherd in its body camera program.

A lifelong cop with a penchant for Harley-Davidsons, Kjos could be a stern task master who demanded the best from everyone who worked for him. He joins his wife, Ann, a former MPD homicide detective, in retirement.

Another notable move is the impending retirement of 4th Precinct inspector Kelvin Pulphus, who took over what's widely considered one of the toughest jobs in the department. In his place, Arradondo elevated Cmdr. Charlie Adams, a Native North Sider, to take over that precinct.

One of Pulphus' top lieutenants, John Delmonico, is also expected to retire. Delmonico, a former police union president, attained local infamy for his involvement in the"pointergate" episode, in which some law enforcement officials accused then-Minneapolis Mayor Betsy Hodges of flashing a gang sign in a picture with a Black voting canvasser who had a criminal past. The episode attracted widespread derision and angered many Black North Siders. But Delmonico gained the respect of colleagues for championing the causes of Black officers during his tenure as police union president.

Cmdr. Katie Blackwell, who commands the training unit, will take over as 5th Precinct inspector from Huffman.

She will be replaced by Lt. Darcy Horn, who leads the department's sex crimes unit and led a push to reduce the department's backlog of unexamined DNA evidence from rape cases.

Cmdr. James Novak will take over Adams' former command of the violent crimes division.

Libor Jany • 612-673-4064 Twitter: @StribJany