By Mark Morales, Andy Rose and Hollie Silverman, CNN

(CNN) -- The Philadelphia Police Department requested that residents in seven districts to stay indoors as demonstrators took to the streets for a second night following the fatal police shooting of Walter Wallace Jr.

Spurts of violence erupted during protests Tuesday, police said, including bricks being thrown at officers. Looting of retail stores in the city also occurred over the last two days.

Wallace, a 27-year-old Black man, was shot and killed Monday while holding a knife during a confrontation with police in West Philadelphia. His family has said he suffered from bipolar disorder and was in crisis during the time of the shooting. A family attorney said Wallace was a mental health patient who was prescribed lithium.

Wallace's family has asked that protesters keep their demonstrations peaceful to respect his memory.

Speaking to CNN's Chris Cuomo on Prime Time Tuesday night, Wallace's father asked that people honor his son's memory and his family's grieving.

"All this violence and looting. I don't want to leave a bad scar on my son and my family with this looting and chaos stuff," Walter Wallace Sr. told CNN. "So I want my son's name and everybody to stop this. Give my son a chance. And the family like we're decent people."

"Everybody to have respect for our family, to pray for us. Cut it out. The looting is a mindset and it won't bring my son back. And it won't, it will escalate things to get worse instead of better," he added.

Violence erupts during protests

A large, peaceful group of protesters marched through the Cobbs Creek section of Philadelphia Tuesday night.

The demonstrators could be heard chanting, with one person yelling, "Who's street?" and the crowd responding, "Our Street!" along with "Say his name!" with the crowd yelling back, "Walter Wallace!"

But the peaceful protest turned violent when the crowd was met by a group of police officers near Philadelphia Police 18th District.

A CNN crew covering the protest witnessed several people in the crowd throw rocks, light bulbs and bricks at the police. The officers retreated, with one clearly injured, blood trailing him.

One protester with an ax moved toward police and hacked at the front of a police car before leaving the area, the CNN crew said.

As the situation escalated, police moved various vehicles into the area and took up posts on the street.

In light of the violence, police requested that people stay indoors. "The Philadelphia Police Department is requesting that all residents in the 12, 16, 18, 19, 24, 25, and 26th Districts remain indoors except when necessary," a tweet from the Philadelphia Office of Emergency Management said Tuesday night. "These areas are experiencing widespread demonstrations that have turned violent with looting."

Police also reported that a large crowd, which they estimated to be approximately 1,000 people, looted businesses in the Port Richmond section of Philadelphia Tuesday night. It is unclear whether they were associated with the protest.

Aerial footage from CNN-affiliate KYW showed people looting a Foot Locker and a Walmart, emerging with televisions and other products.

"Several hundred members of the Pennsylvania National Guard were mobilized to Philadelphia to assist law enforcement amid the ongoing civil unrest Tuesday at the request of Governor Tom Wolf and the Pennsylvania Emergency Management Agency," spokesman Lt. Col. Keith Hickox said in a statement to CNN. Mike Dunn, a spokesman for Mayor Jim Kenney, told CNN the city had also formally requested the assistance of the Pennsylvania National Guard.

Violence and looting also took place Monday night, leading to dozens of arrests and injuries to officers, most the result of thrown objects. One officer was struck by a pickup and taken to the hospital with a broken leg and other injuries, police said.

Businesses were looted, and five police vehicles and one fire vehicle were vandalized, police said. Police Commissioner Danielle Outlaw said 91 people were arrested during the unrest, including 11 on charges of assaulting police and 76 for burglary.

Several businesses in the area, including CVS, closed stores Tuesday night in anticipation of additional demonstrations following damage during Monday night's protests.

Family attorney says 3 calls made to police

The Philadelphia District Attorney's office said in a statement Tuesday it is investigating the fatal officer-involved shooting of Wallace Jr.

The Special Investigations unit responded to the fatal shooting "shortly" after it occurred, and was on scene with other DA office personnel investigating "as we do jointly with the PPD Officer-Involved Shooting Investigation Unit, in shootings and fatalities by other means involving police," the statement from District Attorney Larry Krasner said.

Police said the incident started with a call about a man with a knife, KYW reported. "Responding officers witnessed a male on the block. Immediately they noticed he had a knife in his possession and he was brandishing it, and waving it erratically," Philadelphia Police Sgt. Eric Gripp told KYW.

Shaka Johnson, an attorney for Wallace's family, said relatives had made at least three calls to authorities that day. The initial call for was an ambulance, he said.

"The police are who arrived first," Johnson told reporters Tuesday night. "The call that was initially put into 911 dispatch was for medical intervention. The ambulance never made it."

Johnson said Wallace's brother called for an ambulance and Wallace's wife told police her husband "was in crisis." Relatives said police had been at the address earlier that day.

It's unclear whether police responded to all three calls. CNN reached out to police and the family attorney for clarity.

At a Tuesday news conference, police officials did not answer questions about whether officers were there earlier in the day or had previously interacted with Wallace. They did not say what officers knew of the situation prior to arrival.

Police Commissioner Danielle Outlaw said investigators were reviewing radio calls to determine what the officers knew at the time they responded.

Former top cop: 'It's so complicated'

Former Philadelphia Police Commissioner Charles Ramsey told CNN's "New Day" the case is not as clear cut as some other past police shootings because Wallace was armed.

"Well, I mean, listen, you never want deadly force to be the outcome of any encounter," Ramsey said. "And I can see in the tape that they were backing up and so forth. At some point in time, the distance was beginning to close between themselves and the individual."

Ramsey said the officers had seconds to make "crucial decisions."

"This is why it's so complicated and this is why police need the adequate tools and training, but more importantly there needs to be a beef up of mental health services, not only in Philly, but in cities around the country so that police will not have to be dispatched," Ramsey said.

"But having said that, I can't think of any mental professional that would have done this without calling 911, because the person was armed," he added.

JaHiem Simpson, who took video of the police shooting, told CNN there was some commotion and arguing before police were called.

When police arrived at the man's house, Simpson said a person who he later was told was Wallace's mother told police that Wallace had mental health issues.

Simpson said Wallace exited the house with a knife and everybody told him to put the knife down. Simpson said he saw officers pull their guns as soon as they saw the knife.

The video shows Wallace walk around a parked car into the street, and the two officers can be seen backing up as he walks towards them. Multiple shots ring out as police fire, striking him. Sgt. Gripp told KYW that an officer took Wallace in his police cruiser to Presbyterian Hospital, where he died.

"It could have been dealt with in a different way," Wallace Sr. told CNN Tuesday night, adding he believes the officers "could have called a superior to handle the situation."

Johnson, the attorney for the Wallace family, said that if the officers had had a less lethal option the outcome could have been different.

"The officers did not have what they needed. There wasn't a less than lethal option available. They didn't have Tasers," Johnson explained. "A person is in mental decline and in crisis."

The attorney said additional equipment and training for these situations should be available to officers.

"Every training academy you give officers a badge. You give them a gun. You give them rounds of ammunition. You train them how to kill. You train them how to hit head shots," Johnson said, adding "You (are) setting them up and you are setting the community up. It is a lose-lose situation."