Details are still emerging about the incidents. In all three cases, which resulted in the deaths of African-American men, representatives of the officers involved have said they were physically threatened and acted appropriately.
Prosecutors in Cumberland County, New Jersey, said they're investigating the death of a 32-year-old man who was in police custody.
Police said officers unleashed a K9 on 32-year-old Phillip White when a violent struggle ensued after they were dispatched March 31 to a report of a "disorderly person."
It wasn't long before officers called for medical assistance, according to prosecutors, reporting that White was in respiratory distress. He was pronounced dead at the hospital soon afterward.
"It's a tragedy that's blatantly preventable," said Conrad Benedetto, an attorney representing White's family.
A Facebook page
demanding justice in the case points to cell phone videos of the incident and accuses police of deliberately allowing the dog to maul White to death.
Stuart Alterman, an attorney for the officers involved, said White had PCP, cocaine and other drugs in his system at the time of his arrest, which caused him to act "in a bizarre manner and have superhuman strength."
Officer Rich Janasiak deployed the dog after White grabbed Officer Louis Platania's weapon, Alterman said.
Vineland Police Chief Timothy P. Codispoti said videos of what transpired don't show the violent struggle White had with officers beforehand. He contends that force was necessary, CNN affiliate KYW reported.
After White's death, the police chief released a statement calling the incident a tragedy
but asking the public to withhold judgment until prosecutors complete their investigation.
Mom in dash cam video: 'Please don't hurt my child'
Lavall Hall, a 25-year-old who family members say was a paranoid schizophrenic, died after police shot him in February.
Family members had called police for help tracking down Hall after he left his mother's house.
Now they've filed a civil rights lawsuit against the city of Miami Gardens, its former police chief and the two officers involved in the shooting.
The family's lawyer said video of the shooting makes it clear police went too far.
"There's no question when you view this video that the officers used excessive force in dealing with an individual who had mental issues," attorney Glen Goldberg said.
But Oscar Marrero, an attorney representing Officer Eddo Trimino and Officer Peter Ehrlich in the civil lawsuit, said Hall attacked the officers before one of them opened fire.
In the days after the shooting, Stephen Johnson, then the Miami Gardens police chief, defended the officers.
"Based upon the facts that I have, I think that the officers did the best that they could, confronted with the circumstances that they were encountered with," he said at the time.
The dash cam video captures mother Catherine Daniels' conversation with police before the shooting.
"He has a problem and I'm scared," she tells one officer. "Please don't hurt my child."
The video later shows Hall running toward a police car, broomstick in hand. You can't see everything that happens in the seconds leading up to the shooting, but you can hear the gunfire that ended Hall's life.
The state attorney's office is investigating the shooting.
Shooting into vehicle after police chase
On the same day authorities said a police officer was being charged with murder after a shooting in North Charleston, South Carolina
, another officer was arrested 150 miles away in the town of North Augusta.
Public Safety Officer Justin Gregory Craven is charged with discharging a firearm into a vehicle while occupied.
The case stems from the February 2014 shooting death of 68-year-old Ernest Satterwhite, who was shot dead while sitting in a car in his driveway after a police chase. Police had tried to pull Satterwhite over on suspicion of driving under the influence, the Edgefield Daily reported at the time
, citing police incident reports. Craven shot into the vehicle after reporting that Satterwhite had grabbed his gun during a confrontation. Satterwhite was pronounced dead at a nearby hospital.
In a lawsuit, Satterwhite's family "vehemently denies" that he ever tried to grab the officer's weapon, according to The Washington Post
A grand jury indicted Craven on a misdemeanor charge of "misconduct in office" earlier this year -- a lesser charge than the manslaughter charge prosecutors had been seeking, the Post reported.
On Monday, the South Carolina Law Enforcement Division announced Craven will now face the felony firearm charge, which carries a maximum penalty of up to 10 years in prison and a $1,000 fine.
According to an arrest affidavit
, the shooting was recorded on video and Craven admitted firing into the vehicle.
Craven's attorney, Jack Swerling, told The Washington Post that his client plans to plead not guilty to both charges.