Philadelphia Police Commissioner Charles Ramsey speaking Monday about the federal review. (Matt Rourke/AP)

The Philadelphia police force needs to revamp the way its officers use force in the wake of hundreds of police shootings in recent years, the Justice Department said in a new report that found “an undercurrent of significant strife between the community” and the police there.

This report looked at the number of times Philadelphia police officers shot someone between 2007 and 2013, finding nearly 400 such incidents over that seven-year span. Fifty-nine unarmed people were fatally shot over this period, and half of the unarmed people were shot because the officer saw something (like a cellphone) or some action (like a person pulling at the waist of their pants) and misidentified it as a threat, the report states.

However, investigators say it is impossible to put this number into context, because there is no reliable national data on officer-involved shootings. “Therefore, we cannot say whether this number is high or low,” the report states.

The lack of accurate data on these shootings has been cited repeatedly over the past year, as police shootings in Cleveland and Ferguson, Mo., have sparked demonstrations over the deaths of black men and boys at the hands of police officers. Attorney General Eric H. Holder Jr., who is stepping down (eventually), called the lack of accurate data “unacceptable” earlier this year.

“The troubling reality is that we lack the ability right now to comprehensively track the number of incidents of either uses of force directed at police officers or uses of force by police,” Holder said during a speech.

While it is an inelegant comparison to try to make, the number of police shootings in Philadelphia would seem to be high when compared with other major cities. In New York, for example, there were 30 police shootings in 2012 (16 of the people shot were killed, while the rest were injured) and 25 such shootings in 2013 (eight of those people were killed), according to the police. The Dallas Police Department, responsible for a city closer in size to Philadelphia, said it had 23 shootings in 2012 and 22 in 2013. Meanwhile, police in Philadelphia had 58 shootings in 2012 and 44 shootings in 2013.

Still, the Justice Department report notes that regardless of how numbers may compare with those in other cities, any department should try to lower the number, adding that shootings of unarmed people “are undoubtedly the most controversial” and can lead to protests and reforms.

Some members of the Philadelphia community “do not trust the [police department] or any local partners to conduct a fair and objective investigation,” in part because of the times when police used excessive force and in part because the department has not been transparent with the public, the new review states. To counter this, the Justice Department calls on the city to let an independent outside agency investigate shootings of unarmed people and to hold a news conference within three days of any shooting to release details.

The Justice Department found problems with the way police shootings are investigated, and in the report it urges the department to create a unit charged with looking into every time an officer uses deadly force. A board including an officer who outranks the officer involved in the shooting, an officer on their level and a member of the public should be able to call witnesses and ask questions before voting on a decision, the report states.

In addition, the report said the department needs to improve its policy governing use of force, suggesting a more detailed explanation of what actions should be used and how to react to different threats. This suggestion specifically points out that the department’s policies should explain that some people whom police encounter will be “physically or mentally incapable of responding to police commands,” with language barriers and mental impairment cited as possible explanations for why a person may not comply with police orders.

The report into the country’s fourth-largest police department was released less than three weeks after the Justice Department dropped a blistering review of the Ferguson Police Department. That probe was launched after a white police officer there shot an unarmed black 18-year-old last year, which was followed by prolonged outrage in that Missouri city. The federal review of Ferguson found “intentional discrimination on the basis of race” in the city’s police department and court system, and it was quickly followed by key officials in the city leaving their positions.

This report on Philadelphia’s police force, by comparison, was requested by Charles C. Ramsey, the city’s police commissioner, after Philly.com reported in 2013 that police were shooting more people, even as the number of violent crimes and attacks on police officers dropped. Ramsey was picked to co-chair a White House task force on policing and community relations that was launched in the wake of the Ferguson shooting and the unrest that followed. This task force has recommended independent investigations into all police shootings.

The Ferguson investigation was conducted by the civil rights division (which has investigated more than 20 police departments over the past five years), and if the federal government and city officials are unable to reach an agreement, the Justice Department could file a lawsuit. The Philadelphia document was a technical report conducted by Virginia-based CNA Corp. and released by the Office of Community Oriented Policing Services, which will work with the city’s police to monitor reforms and will publish additional reports over the next year and a half.

“Through enhanced training, improved transparency of deadly force investigations, and strengthened use of force review processes, I am confident the Philadelphia Police Department will see great improvement to its law enforcement policies,” Ronald Davis, director of the Justice Department’s community policing office, said in a statement. “The recommendations presented today benefit not only this department, but can serve as a guide for other police agencies across the country facing similar challenges.”

The report arrives not long after the death of a Philadelphia police officer named Robert Wilson III, who was fatally shot earlier this month when he went to a videogame store to buy his son a game and wound up finding — and trying to stop — an attempted robbery. Wilson was the second officer known to be killed by a suspect this year, after a shooting in Georgia a day earlier of an officer that police described as an ambush.

And the report’s arrival comes as tension recently spiked again in the city over the death of Brandon Tate-Brown, who was fatally shot by two Philadelphia police officers last year.

On Thursday, R. Seth Williams, the Philadelphia district attorney, said he was not going to file any charges, saying that evidence showed that Tate-Brown had been reaching for a gun when he was killed. Later that day, Williams and Ramsey went to a community meeting, but protests gave way to a physical confrontation between residents and police, and 10 people were arrested.

You can read the complete report here.