HARRISBURG — A group of Democrats in the General Assembly said Tuesday shootings by police show the need to change the rules for when Pennsylvania officers can use deadly force and to reform their oversight and training.

Members of the Legislative Black Caucus outlined a legislative agenda that would also include appointing special prosecutors to investigate police shootings. Another proposal would limit the power of arbitrators in police discipline matters.

Several spoke of concerns about the fatal shooting last year of an unarmed black teen by a white police officer who was subsequently acquitted of homicide.

A lawyer for the family of Antwon Rose II, who was shot in the back as he ran from an officer, has attributed the verdict to Pennsylvania's law on the use of force by police, a law he believes is unconstitutional.

The use of force legislation, said Rep. Summer Lee, D-Allegheny, will require de-escalation and nonlethal force options before lethal force is allowed when making an arrest. Lethal force could only be justified to prevent imminent threat to life.

The proposals are being drafted and could face tough questions in the Republican-controlled Legislature.

House Republican caucus spokesman Mike Straub said police or elected officials who abuse power or commit crimes should be held accountable.

"Our members are willing to engage in worthy discussions over how those who abuse power are held accountable, but not at the expense of unfairly burdening the men and women who are willing to make their own sacrifices to keep us safe," Straub said.

Officer Michael Rosfeld had pulled over the vehicle in which Rose was a passenger because he correctly believed it may have been involved in a drive-by shooting nearby.

Rosfeld defense attorney Patrick Thomassey considered the state's lethal force law the key to the case.

"We have to give the police the right to shoot people, we need to do that," Thomassey said. "And there are certain circumstances where they're justified in doing that."

Lindsay Vaughan, executive director of the Pennsylvania District Attorneys Association, said Pennsylvania law on the use of deadly force by police meets state and federal constitutional requirements, and like most other states requires a reasonable belief in the possibility of death or serious bodily injury.

"Pennsylvania's use of force laws strike the necessary and appropriate balance between the constitutional rights of every person and the very real need of law enforcement to protect the community, as well as themselves and their fellow officers when in the line of duty," Vaughan said.

Pennsylvania law says police may also use deadly force if they reasonably believe it will prevent a suspect from resisting or escaping arrest and that the suspect has committed or tried to commit a "forcible felony" or has a deadly weapon and is trying to escape.

Police and correctional officers may use deadly force to prevent a prisoner from escaping, if they have the same concerns about possible death or bodily harm to themselves or others. They can also use deadly force if it would be required "to prevent the apprehension from being defeated by resistance" and if the escapee has been convicted of a forcible felony or has a deadly weapon.

Deadly force can only be used to prevent suicide or the commission of a crime, under Pennsylvania law, if an officer thinks there's a "substantial risk" a suspect will harm or kill someone and the use of force does not put third parties at risk. Deadly force can also be deployed under those circumstances if an officer thinks it's needed to suppress a riot or mutiny, and rioters or mutineers have been told to disperse and warned force will be used if they do not.

Pennsylvania Superior Court in 1990 interpreted the law to say "the statute is not to be read to allow deadly force to be used against a person who poses no threat to human life or safety."