When Jim McDonnell is officially sworn in as the next Los Angeles police chief on Nov. 14, daunting challenges await.

The list includes dealing with powerful union resistance to major disciplinary reforms; scrutiny from oversight officials after a rash of confidence-shaking scandals; and calls to improve relations with communities left mistrustful after decades of adversarial policing.

But for McDonnell — who served a single term as L.A. County sheriff from 2014 to 2018 — that’s all familiar territory.

Although the LAPD and the Sheriff’s Department are worlds apart culturally, longtime observers of both agencies say McDonnell’s resume, which also includes a stint as police chief in Long Beach and 28 years in the LAPD, offers insights into both his managerial style and the potential pitfalls he’ll face.

In introducing McDonnell at a news conference earlier this month, Mayor Karen Bass praised his decades of experience and repeatedly referred to the incoming chief as an “innovator.” But his critics argue that his four years as sheriff suggest he’s unlikely to enact drastic changes as LAPD chief.

McDonnell still requires City Council confirmation and is scheduled to appear before the public safety committee on Tuesday, but his public swearing-in ceremony is already set for Nov. 14.

The LAPD referred requests for an interview with McDonnell to a spokesperson for the mayor’s office, who did not respond to numerous emails. The Times spoke with several of his former Sheriff’s Department colleagues, as well as LAPD veterans, about the incoming chief’s record. He has for the past several years worked at USC, where he ran the school’s Safe Communities Institute.

As sheriff, he came under fire from some progressives who said he didn’t do enough to change the perennially troubled department. At the same time, some of his actions rankled the deputies’ union so much that it poured money into the 2018 campaign to unseat him.

Some wonder how that experience might affect his dealings with the LAPD’s equally powerful union, the Los Angeles Police Protective League, which has been emboldened by Bass’ strong public support in recent months. After approving pay raises for officers, amid warnings of financial risk for the city, the mayor has often spoken publicly about the need for improving officer morale — a common refrain from League officials.

The League, which represents about 8,800 officers, has voiced support for McDonnell, saying he shows the mayor is committed to improving police staffing, boosting officer morale and fixing a “broken discipline process,” which some claim protects top leaders while unfairly punishing the rank and file for similar misconduct.

Earlier this year, Bass vetoed an effort to give the chief more power to fire officers accused of serious misconduct. With disciplinary matters still largely decided by civilian Board of Rights panels, McDonnell could have limited room to maneuver, according to former LAPD Chief and City Councilmember Bernard Parks.

“They’ve gotta clean that [discipline system] up to give him a chance not to just sit there and wring his hands and say, ‘Oh my gosh,’” said Parks, who frequently tangled with the police union over matters of discipline as the city’s top cop from 1997 to 2002.

Parks was chief during the Rampart scandal, which led to court-mandated reforms after officers were found to have committed robberies, murders and other crimes. The next chief, Bill Bratton, chose McDonnell to serve as a top aide.

Greg Yates, a longtime civil rights lawyer, said he was “cautiously optimistic” given how McDonnell helped orchestrate the department’s post-Rampart turnaround.

“He’s survived because he’s very diplomatic and an experienced and intelligent guy,” Yates said.

But if or when McDonnell decides to challenge the status quo, Yates said, “he’s going to be like everyone else, he’s going to get hammered.”

At the Sheriff’s Department, McDonnell aimed to improve honesty and transparency after scandals under Lee Baca.

Baca, who stepped down in 2014, was convicted of thwarting an investigation into his department’s troubled jail system and then lying to federal investigators about it.

McDonnell created an information-sharing agreement with the Office of Inspector General, hired constitutional policing advisors, strove to make sure dishonest deputies got fired and supported the idea of turning over the department’s so-called “Brady list” of problem deputies to county prosecutors.

“He did maintain a very, very high standard about honesty,” said Neal Tyler, who served as undersheriff during the first two years of McDonnell’s term. “I presumed he brought that from LAPD.”

But his tenure as sheriff was also dogged by issues around immigration.

McDonnell opposed a “sanctuary state” bill that aimed to prevent federal immigration agents from taking custody of people being released from California jails. In doing so, he broke ranks with many other local politicians — including the bill’s sponsor, Councilmember Kevin de León, then in the state Senate. It was a massive political gamble at a time when officials found strong support for standing up to former President Trump’s policies.

McDonnell — who at the time described himself to The Times as “not a Trump guy” and “not an anti-Trump guy” — joined other sheriffs who oversee jails in arguing that the proposal was more likely to hurt immigrants than protect them. McDonnell had been a registered Republican in the past, but said during his time as sheriff that he was no longer affiliated with a political party.

Concerns among immigration advocates about McDonnell’s stance have only heightened, with Trump now repeatedly promising mass deportations if reelected.

Other detractors, such as Melina Abdullah, co-founder of Black Lives Matter Los Angeles, pointed to the former sheriff’s failure to improve conditions in the L.A. County jails or more aggressively root out deputy gangs, the unsanctioned groups of tattooed deputies repeatedly accused of misconduct over the years.

As the mayor’s chief search narrowed to two other finalists that included a Black woman and a Latino man, Abdullah said that the other two candidates — Deputy Chief Emada Tingirides, who runs the department’s South Bureau, and former LAPD assistant chief Robert “Bobby” Arcos — had found some support among some progressive groups who were normally leery of law enforcement.

“The jails and the allowance for the expansion of the deputy gangs was so horrible that even these progressive organizations were like, ‘Anybody but Jim McDonnell,’” she said.

Tyler, the former undersheriff, noted that McDonnell won’t answer directly to voters as chief. And he also won’t have to overcome being an outsider, which he struggled with previously as a longtime LAPD member stepping in to lead the county agency.

“He failed to get elected again — that doesn’t matter to LAPD,” Tyler said. “And he failed to be a sheriff’s deputy from day one — that doesn’t matter to LAPD.”

Unlike his predecessors, Tyler said, McDonnell directly involved himself in disciplinary decisions, asking the undersheriff to brief him on every case. He cracked down on unauthorized station logos and imagery, Tyler said, and started the inquiry into deputy subgroups that later gave way to the Rand Corp. report published after McDonnell’s successor had already ousted him from office.

In an email to The Times, former Sheriff Alex Villanueva wished McDonnell luck as chief, and stressed the need for striking a “sensible balance between supporting the officers doing a difficult job and holding them accountable when they don’t meet the standards the community deserves.”

On social media, Villanueva — who was voted out of office himself four years after succeeding McDonnell — struck a snarkier tone. “Hopefully,” he said, “Mr. McDonnell has learned something about how not to run a large organization.”

Villanueva rolled back many of McDonnell’s key reforms, bringing back the controversial “Fort Apache” logo at the East L.A. station, replacing the department’s constitutional policing advisors, clamping down on the sharing of information with oversight officials and creating a group to evaluate terminations and discipline under McDonnell’s term.

Inspector General Max Huntsman, the county watchdog whose office is tasked with overseeing the Sheriff’s Department, said McDonnell’s emphasis on discipline and accountability sparked opposition from the union and made him unpopular with some deputies, while outsiders faulted the lack of a sweeping overhaul.

“He didn’t wanna come in as an LAPD guy and just say we’re gonna do it this way, the LAPD way,” Huntsman said. “So he took his time and as a result I think was perceived as being too slow.”

Keith Swensson, a former commander in the Sheriff’s Department, said that McDonnell never “really had enough time to make major changes.”

“He definitely tried,” Swensson said. “He kind of had more discipline than what the department had before he arrived. But did that really change the department that much? I don’t think it did.”