Springfield's Police Commissioner is pushing back against the U.S. Department of Justice's investigation into police brutality, especially within the Springfield Police Department's narcotics unit. WGBH Morning Edition host Joe Mathieu spoke with Northeastern University law professor and WGBH News legal analyst Daniel Medwed to explain the federal investigation. The transcript below has been edited for clarity.

Joe Mathieu: Let's try to get a sense of the basics here. First of all, how do these federal investigations begin? How do they work?

Daniel Medwed: Well, while the police are usually monitored at the state and local level, the federal Department of Justice does have jurisdiction to conduct these types of investigations if they detect what's called a pattern or practice of federal constitutional violations, like the repeated use of excessive force.

So what usually happens is the DOJ takes a deep dive into the department. They scour through every record in the personnel files, they familiarize themselves with internal departmental policies, they interview stakeholders and so on, and then generate a report that contains its findings and recommendations. Sometimes they even install an independent monitor to supervise the department temporarily while the two sides negotiate what's called a consent decree, which is enforceable in federal court and basically provides a roadmap to resolving the particular problems in the department.

Mathieu: So is this a rarity or is it very common for DOJ to conduct one of these pattern or practice, as you call it, investigations?

Medwed: It really depends, I think, on the worldview of the particular president and attorney general in office at the time. So during the Obama administration, his DOJ used this tool about 25 times to investigate problematic police departments, including most famously in Ferguson, Missouri, after the shooting death of Michael Brown in 2014. That process generated not only a 100-plus page report — a scathing one, at that — but also a consent decree that implemented new use of force policies and a bias-free policing model.

Now President Trump, perhaps unsurprisingly, uses this investigative tool far more sparingly. In fact, believe it or not, the Springfield investigation is the only pattern or practice investigation undertaken by the Trump administration since he took office in January 2017.

Mathieu: So Springfield's looking pretty special this morning.

Medwed: We could say that.

Mathieu: You just mentioned that Springfield's the only local department they've investigated. Let's talk about some of the findings. What was going on inside?

Medwed: Well, as you alluded to at the top, that the Springfield Police Department has a remarkably disturbing history, especially within its narcotics unit, which is a subgroup of plainclothes officers.

DOJ conducted a 27-month investigation here before producing a report that really pulls very few punches. I'll quote some of the key findings because they are incredibly alarming: that narcotics unit officers "repeatedly punch individuals in the face unnecessarily"; "they escalate encounters with civilians too quickly"; [and] "they resort to unreasonable takedown maneuvers that could reasonably be expected to cause head injuries."

What's more, DOJ attributed these bad actions in part to systemic deficiencies within the department itself. So unlike most police departments, officers in Springfield aren't required to report every hands-on use of force incident, like a punch or a kick, unless it results in an injury. And even if they do file a report because the incident culminated in an injury, the command staff seldom refers those reports to internal affairs. In fact, data from 2013 to 2018 revealed that not a single report was referred to the internal investigations unit, as it's called there, despite ample public complaints of police brutality throughout Springfield and even a few criminal cases against Springfield police officers.

Mathieu: It's like watching the movie Training Day. What happens next? The DOJ made some recommendations, Daniel. Do they have to follow them?

Medwed: That's an excellent question. So the DOJ made four concrete suggestions that, in its own words, "must be made", most notably new procedures for reporting all uses of force, and ensuring that supervisors actually take those reports seriously and refer them to internal affairs. Also, DOJ insisted that officers undertake a more enhanced and robust use of force training regime.

Now, whether the Springfield police will actually implement these reforms, of course, remains to be seen. It also remains to be seen whether DOJ will bring in some teeth to actually force Springfield to adopt these changes. Nevertheless, I think this is a promising step — maybe a baby step — on the path to overhauling this deeply troubled police department.