The move comes months after the state American Civil Liberties Union complained of rampant misconduct and lax internal oversight at the Newark Police Department, although federal and city officials insisted that the ACLU's petition wasn't the main reason for the probe.
"We receive information from a wide array of sources and have jurisdiction to determine whether we should move forward at a fuller level, and we've determined it's important to move forward," said Thomas Perez, assistant attorney general for the Civil Rights Division of the DOJ. "Having said that, we'll follow the facts where the facts take us."
U.S. Attorney Paul Fishman said the probe will look into allegations of excessive force, discriminatory policing and poor treatment of detainees in holding cells. They will also investigate whether officers retaliate against those who legally observe, or record, police activity.
Fishman said justice officials will work with police, community members and other stakeholders to determine "whether there are systemic violations of the constitution or federal law" by the Newark Police Department.
In a 96-page filing to the DOJ in September, the ACLU called for federal oversight of the city's 1,300-officer department.
Newark Mayor Cory Booker said he welcomed the investigation, adding that he saw it as a form of additional federal help with the city's crime problem.
Newark has long been one of the most violent and poorest cities in New Jersey. Its violent crime rate fell dramatically in 2008 and 2009, but has inched upward in the past two years. The city recorded 28 murders through the end of April, a 65 percent increase over the same period a year ago.
Newark laid off more than 160 police officers at the end of last year to close a budget gap, marking the city's largest force reduction in 32 years. Last week, Garry McCarthy, Newark police director since 2006, was selected by incoming Chicago Mayor Rahm Emanuel to be police superintendent of the nation's third-largest city. Deputy Chief Samuel DeMaio, a longtime law enforcement officer in the city, has been named acting police director in Newark, a city of 280,000 residents.
The ACLU filing cited 418 instances of misconduct that included officers breaking a man's jaw and eye socket during an arrest and seven deaths attributed to Newark officers. The deaths included shootings or ignoring urgent health complaints, the filing said. The organization said that out of 261 complaints filed with the police department's internal affairs division between 2008 and 2009, only one complaint, alleging an improper search, was found credible.
The ACLU petition also said the city had paid $4.8 million over 2 1/2 years to settle 38 cases brought against police by residents or department employees, with at least three dozen lawsuits pending.
Deborah Jacobs, executive director of ACLU's New Jersey chapter, said Monday that the ACLU had been calling for federal intervention in the Newark Police Department since 1967.
"The announcement that the DOJ will bring its resources and expertise to our city and hold the NPD accountable marks a critical moment in our city's history," Jacobs said. "The cries of Newarkers have finally been heard."
Newark police and city officials called the allegations frivolous and inaccurate when the ACLU petition was filed, arguing that the group skewed the data and is exaggerating problems that the city for years has been working with the ACLU to address.
Message left Monday for representatives of the Fraternal Order of Police in Newark weren't immediately returned.