The Department of Justice announced in a press conference Thursday it is opening a "pattern or practice" investigation into the city of Phoenix and the Phoenix Police Department.

Driving the news: The Justice Department's probe comes after the Biden administration reversed a Trump policy of not investigating police departments. It looks into several possible violations exhibited by the city's police department:

• Whether the city's police department uses excessive force;
• If the Phoenix police department engages in discriminatory policing practices;
• Whether the department violates first amendment rights by "retaliating against individuals who are engaged in protected, expressive activities," Attorney General Merrick Garland said at Thursday's press conference;
• Whether the city and its police department respond to people with disabilities in a way that violates the Americans with Disabilities Act;
• If the department "unlawfully seizes or disposes of the belongings of individuals experiencing homelessness."

The big picture: The investigation's broad focus highlights the ways in which law enforcement is strained by virtue of being the first responder to larger societal problems, Garland said.

• "Too often we ask law enforcement officers to be the first and last option for addressing issues that should not be handled by our criminal justice system," he said.
• "This makes police officers' jobs more difficult, increases unnecessary confrontations with law enforcement, and hinders public safety," the attorney general added.
• "Far too often police officers are the first ones called when someone is experiencing a mental health crisis in any setting, but it is almost certain that police will be called to someone experiencing a mental health crisis if that person is also without housing."

The investigation will include a review of police department reports, data and body camera footage, as well as meetings with members of the force and broader Phoenix community, noted Assistant Attorney General Kristen Clarke.

• The probe will also look into repercussions that law enforcement officers accused of misconduct face, Clarke added.
• The DOJ briefed Phoenix Mayor Kate Gallego and Police Chief Jerry Williams about the investigation and both pledged their support, Garland noted.

The other side: In a statement issued Thursday, Gallego "welcomed" the investigation and noted that police reform has been an ongoing goal during her time in office.

Our thought bubble via Axios' Russell Contreras:The move fulfills a Biden administration promise to restart pattern or practice investigation into law enforcement agencies to force some into consent decrees to address excessive force cases.

• The Phoenix Police Department and the Maricopa County Sheriff's Office have notorious reputations as agencies that target Mexican Americans and Latino immigrants. Activists have long asked for federal investigations.

Flashback: The Justice Department under President Obama entered a consent decree with Albuquerque in 2014 following an investigation that found its police department used excessive force against people suffering from mental health issues.

Don't forget: Most police agencies in recent federally court-ordered reform agreements saw violent crime rates skyrocket immediately, according to an Axios examination of departments under consent decrees since 2012.

• The increases in violent crime rates suggest there can be unintended consequences, at least in the short term, to the policing changes many Americans demanded in the year since George Floyd's death.