BALTIMORE (WJZ) — Police shake up. Kevin Davis is Baltimore’s new top cop after the mayor names him the interim commissioner. But he now faces major problems. The department is under federal investigation, as violent crime spikes amid low morale.

WJZ Investigator Mike Hellgren with what’s next for the Baltimore Police Department.

Davis says he is not going to make change for change’s sake. He’s got to get crime under control–that’s the bottom line–here in Baltimore.

In his first full day on the job, Interim Commissioner Kevin Davis met with State’s Attorney Marilyn Mosby and told WJZ he wants to lead the department permanently.

“I wouldn’t have taken this job if I thought for one second I couldn’t do it,” said Davis.

“We’re already on the same page. We’re going to focus on the worst of the worst–the violent, repeat offenders–and we’re going to continue to move our city forward,” said Mosby.

Davis inherits huge challenges from his predecessor, Anthony Batts, including a disgruntled rank and file and a union outraged about the riot response.

RELATED: Police Commissioner Anthony Batts Fired As Baltimore Sees Alarming Violence Spike

“Loss of trust from the rank and file, the community begins to call for your ouster and crime goes up. That’s the trifecta. And when that occurs, you’re going to lose your job,” said Rob Weinhold, police expert, Fallston Group. “If you’re a police commissioner and you don’t reduce crime, you will be removed from office.”

Since 2000, the average Baltimore City police commissioner has lasted just two and a half years.

Norris, Clark, Hamm, Bealefeld and Batts all faced upheaval in a department where there’s been no shortage of scandal.

“In any appointed position, politics are at play–there’s no doubt about it. The best thing that could happen is for elected officials to monitor, but let the police department do its job,” Weinhold said.

“Do you know how long I’ve been the police commissioner? About a day,” asked Davis.

RELATED: Who Is Baltimore’s Interim Commissioner Kevin Davis?

In that short, Davis has already named a commander as his point person for civil unrest and is determined not to repeat mistakes made responding to the unrest following Freddie Gray’s death.

But the attorney representing Gray’s family says new leadership is not enough and wants the feds to take over the department now.

“Nothing short of that will solve the problem. It’s so dysfunctional, so at war with itself,” said Gray family attorney Bill Murphy.

A statement from the union says they will work with Davis to try to built unity in the department.