The 180-page document was allegedly written by the suspect and posted online just before the mass shooting

Investigators believe the suspect was in Buffalo a day before the shooting and did some reconnaissance at the Tops Friendly Markets store, Buffalo Police Commissioner Joseph Gramaglia said. They also believe he acted alone, Gramaglia said.

Kelly Galloway’s family shops at the grocery on Saturday mornings, she told the station. “That could have been our mothers, our grandmothers, our aunts, our uncles,” she said. “And it was us. It was us.”

Buffalo Mayor Byron Brown spoke Sunday to worshipers at a church, saying of the slain: “Their lives and their example should be examples to us, that we have to love more, we have to care about each other more because we don’t know when our time might come.”

Those at the supermarket “were going about their daily lives, left in the morning and had every expectation that they’d be home at night with their families,” he said. “Many of us stood shoulder to shoulder yesterday in pain, like all of us are in pain, dealing with the aftermath of this horrible, racist, violent attack on our community.”

More about alleged manifesto emerges

“We continue to investigate this case as a hate crime, a federal hate crime, and as a crime perpetrated by a racially motivated, violent extremist,” Stephen Belongia, special agent in charge of the FBI Buffalo field office, said Sunday at a news conference.

The gunman began a livestream of the attack, with the video removed less than two minutes after the violence began, livestreaming service Twitch said in a statement to CNN.

Authorities will be “looking at extensive digital platforms, computers, phones, cameras and anything else that comes into play in this investigation,” Gramaglia said Sunday.

“The evidence that we have uncovered so far makes no mistake that this is an absolute racist hate crime. It will be prosecuted as a hate crime,” Gramaglia said. “This is someone who has hate in their heart, soul and mind.”

The manifesto’s author also writes the supermarket in Buffalo is in a ZIP code that “has the highest black percentage that is close enough to where I live.”

The ZIP code that includes the store, 14208, is 78% Black — the highest percentage of Black population of any ZIP code in upstate New York — the US Census Bureau’s 2020 American Community Survey finds. The shooting suspect is from the town of Conklin, a three-and-a-half-hour drive from Buffalo.

The manifesto also states the suspect bought the main gun he used, a Bushmaster XM-15, from a gun store before “illegally modifying it.”

“We are obviously going through (the manifesto) with a fine-toothed comb and reviewing that for all evidence,” Erie County District Attorney John Flynn told CNN.

The suspected gunman had been on the radar of police about a year ago, officials said.

As a student last June at Susquehanna Valley Central High School, he made a “generalized threat” that was not racially motivated, Gramaglia said. The student was brought in for a mental health evaluation and released after a day and a half, he said.

The New York State Police investigated and responded to a report that a 17-year-old student had made “a threatening statement” in June at the same high school, an agency spokesperson confirmed to CNN. The student was taken into custody and to a hospital for a mental health evaluation.

Entire community affected by mass shooting

Saturday’s attack stunned those who live in the heart of the Kingsley and Masten Park neighborhoods.

Geraldine Talley, 62, was doing her regular grocery, shopping with her fiancé Saturday when she was shot and killed, her niece Lakesha Chapman told CNN.

“She’s sweet, sweet, you know, the life of the party,” Chapman said. “She was the person who always put our family reunion together, she was an avid baker … mother of two beautiful children.”

“We’re outraged,” she added. “This is not, obviously, the first racially triggered attack in America. However, it is the first that hits our home.”

New York Gov. Kathy Hochul announced $2.8 million for the victims and their families, her office said in a statement.

“The entire world is watching how we will come together as New Yorkers to overcome this unthinkable tragedy. Buffalo, my hometown, is the City of Good Neighbors and New York State will be good neighbors for them,” she said.

With the grocery closed because of the investigation, Tops Markets is working with a representative of the Masten District to secure free food and supplies, plus free transportation, for those in need it, it said.

The mayor called the site “near and dear” to his heart.

“It’s one that I patronize from time to time,” Brown said Saturday, “my family patronizes from time to time, and some of the victims of this shooter’s attack are people that all of us standing up here know.”