(CNN) -- Albuquerque, New Mexico, police officers killed a 19-year-old as he "lay motionless on his back," an unarmed drugstore robber who was walking away from officers and a 25-year-old veteran suffering from post-traumatic stress disorder who threatened to shoot himself in the head.
So says the U.S. Justice Department, which on Thursday issued a report lambasting the Albuquerque Police Department for a longstanding history of police brutality and unnecessary deadly force.
The 19-year-old, Andrew Lopez, caught Albuquerque police officers' attention while driving with dim headlights and no taillights; when police tried to pull him over, he led them on a low-speed chase before parking and taking off on foot, the report said.
Five officers gave chase, and when Lopez reached a fence and began to turn around, one of the officers fired three times, hitting Lopez once. The nonlethal shot put Lopez on his back, the report said, and the officer approached him and fired a fourth shot into his chest, killing him.
The February 2009 incident, which resulted in a $4.25 million payout to Lopez's estate, is one of several incidents the Justice Department cites in concluding that the Albuquerque Police Department "has engaged in a pattern or practice of excessive force, including deadly force."
Requests for comment sent to the police department and New Mexico Gov. Susana Martinez's office were not immediately returned, and Phil Sisneros, a spokesman for state Attorney General Gary King, said in an e-mail, "Our office did not have a role in the DOJ's report or investigation. We are looking into a couple of the most recent police-involved shootings, but that is in the nascent stages."
Police brutality in New Mexico's most populous city made headlines last month when protesters clashed with police in riot gear for more than 12 hours over the fatal shooting of the homeless James Boyd, 38.
After the protests, Kenneth Ellis, the father of the suicidal veteran killed in 2010, told CNN affiliate KOAT that police brutality had reached "crisis" levels in Albuquerque.
"Our police department is out of control. They need help with their tactics," Ellis said.
Thursday's report did not address the Boyd shooting, which is the subject of a separate federal investigation.
"The pattern and practice is the result of serious systemic deficiencies in policy, training, supervision and accountability. The police department's failure to ensure that officers respect the Constitution undermines public trust," the report's summary says.
In the Lopez case, police said they thought he was involved in a prior incident involving a gun, and the officer who shot him said that when he confronted Lopez, he believed Lopez was carrying "the biggest handgun he had ever seen." The car Lopez was driving did not match the make, color or type of vehicle used in the previous incident, and Lopez turned out to be unarmed, the Justice Department report says.
"For too long, Albuquerque officers have faced little scrutiny from their superiors in carrying out this fundamental responsibility," the report says. "Despite the efforts of many committed individuals, external oversight is broken and has allowed the department to remain unaccountable to the communities it serves."
To conduct its review, the Justice Department "reviewed thousands of pages of documents, including written policies and procedures, internal reports, data, video footage, and investigative files," the report says. It also interviewed command staff, rank-and-file officers and community members, and held four community meetings where residents "provided their accounts of encounters with officers."
The report had four major findings:
• The department's officers "too often used deadly force in an unconstitutional manner," and of the 20 fatal police shootings since 2009, most were not constitutional.
Albuquerque police not only use deadly force when there's no imminent threat of bodily harm or death, they also "used deadly force against people who posed a minimal threat, including individuals who posed a threat only to themselves or who were unarmed. Officers also used deadly force in situations where the conduct of the officers heightened the danger and contributed to the need to use force."
• The department's officers also use less-than-lethal force unconstitutionally. A review of 200 use-of-force reports since 2009 indicates that officers use Tasers on people who are nonthreatening, posing minimal threat, passively resisting or "unable to comply with orders due to their mental state."
In one instance, officers used Tasers on a man who had doused himself in gasoline, setting him on fire and endangering everyone in his vicinity.
Officers also use "takedown procedures" in ways that increase harm, and they "escalate situations in which force could have been avoided had they instead used de-escalation measures."
• Officers used a "significant amount of force" against people with mental illness and in crisis. "APD's policies, training and supervision are insufficient to ensure that officers encountering people with mental illness or in distress do so in a manner that respects their rights and is safe for all involved."
• Instances of officers using excessive force are "not isolated or sporadic." The pattern of police conduct suggests "systemic deficiencies in oversight, training, and policy. Chief among these deficiencies is the department's failure to implement an objective and rigorous internal accountability system. Force incidents are not properly investigated, documented or addressed with corrective measures."
To that end, the Justice Department investigators said they found "only a few instances" of supervisors scrutinizing use of force and seeking investigations. In almost all of the cases reviewed, supervisors endorsed their subordinate's version of events even if an officer's account was incomplete, inconsistent with evidence or "based on canned or repetitive language," the report said.
The Justice Department lays out several remedies to address the department's "deficiencies," including improving use-of-force policies, training procedures, internal investigations, recruitment protocol and how it deals with individuals suffering from mental illnesses.
The U.S. Attorney's Office for New Mexico and the Justice Department's Civil Rights Division launched their probe in November 2012, and then-Police Chief Ray Schultz released a statement saying his department was cooperating with federal investigators.
"We know that we are not always perfect and that there is always room for improvement," Schultz said in his statement.
Schultz stepped down in 2013 and was replaced by Gordon Eden, a former U.S. marshal and state public safety secretary, this year.
CNN's John Newsome, Shawn Nottingham and Ashley Fantz contributed to this report.