As the streets outside his home echoed with pops, Darryl Steplight thought it was fireworks on the eve of the Fourth of July. He quickly learned otherwise. A man in body armor, and carrying an AR-15-style rifle, had opened fire at random in the neighborhood, killing five and wounding two, including a 2-year-old.
The man who was arrested and charged with carrying out the rampage was Kimbrady Carriker, whom Mr. Steplight had met just last week.
The encounter was unremarkable, Mr. Steplight said, except for one curious detail: Mr. Carriker, who was wearing a green military-style vest, had introduced himself as a “town watchman.”
On Wednesday, two days after the mass shooting in southwest Philadelphia, the city was trying to understand what had touched off such an inexplicable outburst of violence. In the morning, Mr. Carriker, 40, was arraigned, appearing by video in a white jumpsuit and offering terse responses as a magistrate read out the charges, including murder, attempted murder and reckless endangerment. He was ordered held without bond.
At a news conference in the afternoon, prosecutors said that people who lived with Mr. Carriker had told investigators that he had been “exhibiting abnormal behavior” and “getting more and more agitated” in recent days, even wearing his bulletproof vest around the house. A search of his home, said Robert Wainwright, an assistant district attorney, turned up a will that Mr. Carriker had written, dated June 23. Mr. Wainwright did not say what was in the will.
The authorities said that when Mr. Carriker was arrested he had an AR-15-style rifle and a so-called ghost gun, made from untraceable parts, though investigators had yet to determine how he obtained the firearms.
Prosecutors said the ghost gun was not fired during the shooting, and that a handgun and ammunition were found during the search of Mr. Carriker’s home. Mr. Carriker did not have a license to possess guns, prosecutors said.
Mr. Wainwright said at least one of the seven people who shared a house with Mr. Carriker had recognized that he was becoming more disturbed. But another prosecutor, Joanne Pescatore, said “their way of dealing with it was just to avoid it and not interfere with him.”
Pennsylvania does not have a “red flag” law, which allows families or law enforcement to seek a court order temporarily seizing guns from people deemed a threat to themselves or others. But officials encouraged people to report troubling behavior anyway, suggesting that Mr. Carriker might have gotten help had the authorities known of his behavior. After a 2004 misdemeanor conviction for carrying a gun without a license, Mr. Carriker had apparently spent his life largely off the radar of local law enforcement.
He was, however, a familiar figure to his neighbors on the block of two-story rowhouses where he had been living. They remembered him as friendly and at times helpful. “He never gave us a problem, he was always a nice guy,” said Bernard Mason, 53, who lives across the street. “We saw him a couple of times in full heels and a dress and didn’t think nothing of it, that’s his thing.”
Mr. Carriker appeared in women’s clothing in some photos on his Facebook page, possibly contributing to confusion over his gender identity in the initial hours after his arrest. The district attorney’s office said on Wednesday that they had seen no information to suggest that he considers himself anything but male.
It was on social media that Mr. Carriker’s state of mind may have been most visible to people outside his home. His Facebook page suggests a libertarian-shaded politics, with memes disparaging President Biden alongside posts in support of the Black Lives Matter movement, and through it all support for unrestricted gun rights.
In the days leading up to the mass shooting, his Facebook activity — posts about being followed by evil spirits, alongside articles about efforts to address gun violence in Philadelphia — may have reflected the agitation that the prosecutors described.
“But we prayed to our God and posted a guard day and night to meet this threat,” read a post from last Saturday, two days before the shooting. It was followed by an excerpt from the book of Isaiah: “To save you, I will send an army against Babylon,” read one verse. “I will break down the city gates; and the shouts of her people will turn into crying.”
Jon Hurdle contributed reporting. Kirsten Noyes contributed research.