The New Haven Police Department will move 21 officers from its investigative division to patrol as it rolls out its community policing strategy throughout the Elm City’s 10 districts.

NHPD Chief Dean Esserman and Mayor John DeStefano Jr. announced their plans for the department at a Thursday morning press conference at the Newhallville police substation, paving the way for walking beats for officers to return in full force. To help bolster the department’s numbers, DeStefano also announced that he would present the Board of Aldermen with a budget amendment that would enable the NHPD to add an estimated 40 to 45 new officers to its ranks by taking on two new police academy classes concurrently.

“Everybody will walk a beat, including the chief of police,” Esserman said, adding that the Newhallville beat was the first beat he walked upon returning to New Haven as police chief — Esserman had served as an NHPD assistant chief 18 years earlier. “I expect trust to begin to develop again.”

DeStefano said last year’s homicide rate — the city saw 34 murders, the highest figure since 1994 — made it “clear” the police department needed a change in tactics. He said the money for his proposed budget amendment to expand the NHPD, which he will send to the board within 30 days, would come transfers of funds from other city departments.

NHPD spokesman David Hartman admitted that the proportional workload of the investigative services division — which currently numbers 41 but would drop to 20 after the transfers announced Thursday — would likely increase. But because police calls are investigated by both patrol officers and detectives, the increase in the patrol division would balance out the reduced numbers of plainclothes officers in following up on leads, he explained.

The patrol division will see its numbers swell further with the addition of a double class of officers from police academy. The New Haven police academy will have an intake of 40 to 50 officers in April or May, Hartman said, and the NHPD has secured around a dozen spots at the Connecticut Police Academy in Meriden, Conn., for extra officer training.

Each of the NHPD’s 425 officers will also walk a beat in some fashion, regardless of rank, Esserman said.

Three of the four officers who started walking the Newhallville beat Thursday afternoon were present at the press conference.

“If the vision that the chief has comes to fruition, I’m excited,” said four-year officer Scott Shumway, who walked the Newhallville beat Thursday.

While Shumway said he was familiar with “bad guys” in Newhallville after patrolling the area in his car, but added he was looking forward to building relationships with the “good people” that make up the majority of the neighborhood.

Esserman has spearheaded these efforts to bolster the NHPD’s patrol operations, Hartman said. Since he was sworn in on Nov. 18, Esserman has made the reintroduction of community policing tactics — most visibly, in the reimplementation of walking beats and community meetings — his top priority.

“There’s no question that [Esserman’s] taking charge,” Hartman said. “He’s out there, he’s walked the beat with numerous officers, spent time in the neighborhoods with district managers, identifying problems and coming up with solutions.”

On Wednesday, Esserman heard about several safety and policing problems at a community meeting at the K-8 Wexler-Grant Community School in the Dixwell neighborhood. There, residents raised several concerns to the chief: poor street lighting, the lack of visibility of officers in neighborhoods, the intersection of narcotics and violence, and NHPD officers’ use of Tasers.