For the first time, a federal judge will monitor the Miami Police Department to enforce sweeping institutional changes involving use of force, after the U.S. Justice Department Tuesday found that several police-involved shootings were unjustified during a four-year period.

The Justice Department took the unprecedented step after reviewing 33 police shootings of individuals — including seven black men killed in the inner city — as part of a lengthy civil rights investigation of Miami police practices from 2008 through 2011.

Federal officials agreed with the police department’s own findings that three of the 33 shootings were “unjustified,” but concluded that an unspecified number of others involved excessive force, too, and “may have resulted from tactical and training deficiencies,” said the letter of findings, signed by Assistant Attorney General Thomas E. Perez.

Miami U.S. Attorney Wifredo Ferrer said the Justice findings serve a “dual goal of shining a light on past wrongs and — more importantly — setting a clear course for the future that will assure the residents of the city of Miami that this type of behavior will not be repeated in our city.’’

Former Miami Police Chief Miguel Exposito, who was in charge during much of the timeframe in question, bristled at the findings, saying they failed to reflect the realities of policing high-crime areas of the inner-city.

“Whoever did this probe has very little understanding of what police officers do on a daily basis,” he said, defending the decisions he made to aggressively target crime hot-spots with plainclothes detectives — some of whom shot people.

But U.S. Rep. Frederica Wilson hailed the report as an embarrassing wake-up call that city leaders need to take seriously.

“They described a very dysfunctional police department, a police department that is ingrained in excessive and deadly force,” said Wilson, who had called for federal authorities to delve into Miami police practices. “I’m ashamed of what we have been dealing with.”

Justice, which launched the investigation in November 2011, found that the 1,100-officer department engaged in an unconstitutional “pattern or practice’’ of excessive use of force. Justice also found that a number of practices, including improper actions by specialized units and “egregious’’ delays and major deficiencies in deadly-force investigations, contributed to the problem.

No officers were identified in the report. Justice officials indicated that certain officers implicated in the unjustified shootings are being investigated by federal or state authorities for potential criminal wrongdoing. However, officers in five of the seven fatal-shooting cases have been cleared by the Miami-Dade State Attorney’s Office.

Now, federal authorities will review the civil rights violations with top police officials to draw up a list of reforms that will be overseen by a federal judge in Miami. The judicial review, which could last more than two years, is akin to a court-enforced decree.

When the Justice Department opened a similar civil rights investigation into Miami police shootings more than a decade ago, federal officials did not find a “pattern or practice’’ of excessive force, but uncovered “serious deficiencies” in the police department’s investigations. Federal officials later found that the department had made “dramatic improvements” — including a 20-month period between 2002 and 2004 when no police officer discharged his firearm.