NEW YORK (CBSNewYork) — Mayor Bill de Blasio said the man accused in a deadly crime spree in Astoria, Queens over the weekend did not have a history of violence.

Charges are pending against 23-year-old James Patrick Dillon in connection with three violent attacks on Sunday — one of which left a liquor store owner dead.

De Blasio said Dillon’s record involved some minor criminal offenses, but not involving violence.

“From what we know, this is not someone who would’ve come up on the radar as a particular threat,” de Blasio said Monday. “This horrible tragedy over the weekend is not only very painful, but also very complex because the individual had no history of significant violence.”

A source said Dillon is bipolar and was off his medication during the ordeal, 1010 WINS’ Carol D’Auria reported Sunday.

De Blasio wants to reevaluate the city’s mental health services following the attacks. He noted for decades, mental health problems have been stigmatized and gone untreated.

“Anyone who wants an overnight solution has to look at the fact that this was bluntly ignored for decades,” de Blasio said. “We need to do a much better job…at identifying when someone has a problem and getting them the help they need.”

De Blasio said work is underway to formulate comprehensive mental health responses, but acknowledges more must be done. The mayor said the city is going to take the issue “head on.”

By the end of Sunday’s six-hour rampage, one person was dead and four others were injured, including two police officers.

Dillon’s first victim, 39-year-old Berta Carpio, was slashed on the cheek and in the back of her head around 11:30 a.m. Sunday. The mother of four was a few feet from her home on 36th Street and walking to church when she was attacked.

The worst of her injuries is a 1 1/2 inch wide gash at the back of her skull.

CBS2’s Magdalena Doris spoke to Carpio’s daughter, who translated her mother’s words.

“She didn’t notice that she got cut here [pointing to cheek]; she noticed when she got stabbed in the back of her head and that’s when she saw blood,” the victim’s daughter, Deisy Carpio, said. “When she saw the blood, he also saw the blood at the same time and he just ran away.”

Around 3:09 p.m., police said Dillon continued his violent spree at Astoria Liquors and Wines on Astoria Boulevard near Steinway Street. The owner, 55-year-old George Patouhas, was stabbed to death inside the store.

“This could happen to anybody, anywhere. This is awful. He’s a nice man, who has lived here forever,” Patouhas’s neighbor said.

Dillon is also accused of dousing a 61-year-old homeless man with flammable liquid inside the store and setting him on fire, police said. He was taken to NewYork-Presbyterian/Weill Cornell Medical Center and was listed in stable condition.

Two hours later police got a call to an apartment on 42nd Street and Newtown Road where a woman reported a man was trying to break into her home and climb down her fire escape.

By 5:45 p.m., police had Dillon surrounded near his home. He was armed with a knife and a Corona beer bottle full of flammable liquid, police said.

Officers ordered Dillon to drop the knife, but he refused. He then splashed the officers with the liquid, burning their hands and face, police said.

Officers opened fire and Dillon was shot.

The knife he’d been holding was found in the backyard of his parents’ home, police said.

A knife police believe was used by James Patrick Dillion in a series of violent attacks in Astoria, Queens on Sunday, March 6, 2016. (Credit: NYPD)

A knife police believe was used by James Patrick Dillion in a series of violent attacks in Astoria, Queens on Sunday, March 6, 2016. (Credit: NYPD)

Neighbors said Dillon was a troubled kid.

“He threatened me,” said Doreen Nasr, who has known Dillon since he was a child. “He said, ‘If you talk to my parents I’ll kill you.’”

Nasr said Dillon, whose nickname in the neighborhood was “Soda Pop,” once attacked her son.

“When he punched my son and knocked him on the floor right in front of me, right here in the living room, that was the last straw – do not come back,” Nasr said, “And I told my son to stay away from him. There’s going to be trouble because he acted crazy.”

The officers involved in the incident have been treated and released from the hospital, police said.