Federal officials have found that the Miami Police Department engaged in a pattern of excessive force that led to a high number of shootings by officers, among them episodes that resulted in the deaths of seven young black men over an eight-month period in 2011. 

The findings, released on Tuesday, came after a two-year investigation by the Justice Department’s civil rights division, and they identified “troubling” practices, including delays in completing investigations of officer-involved shootings, questionable police tactics and a lack of adequate supervision. ...