Officials did not have an explanation Tuesday for the discrepancy. Christie and other officials focused on major crimes such as homicide and robbery.
Camden's city police department was disbanded in April 2013 to make way for the Metro Division of the newly created county force.
County officials said the arrangement would allow for more officers than the city department, which toward the end had fewer than 230. Opponents of the move said it was intended to dismantle the police union.
On Tuesday, the county force, which had grown to 320 officers, added 70 to its ranks following a graduation ceremony at Camden County College filled with drums and bagpipes from the police academy.
"It is your class that will finally bring the ranks to full staffing and finally be able to deliver on that promise" of reducing crime, state Attorney General Paul J. Fishman told the newest recruits.
Earlier, in front of City Hall, Christie praised the caliber of the force, saying that 50 percent of the new recruits have a four-year degree. He also commended the department's use of technology, including license-plate scanners and "eye-in-the-sky" cameras, and its outreach to the community.
The Republican governor - who also said Tuesday that he expected to return to Camden "a number of times" in the coming months for economic-development announcements - lauded the commitment of local Democratic officials, including Mayor Dana L. Redd.
He praised them for "improving police services and curbing the crime epidemic that has beleaguered this city and its citizens for much, much too long."
Redd, speaking at the event, praised Christie's attention to the city, saying the governor "has Camden in his heart."
Camden has made "advances and gains" under the new police force, Redd said. And "public safety remains our number-one priority."