The suspect in Monday's deadly mass shooting in Philadelphia was charged with murder Wednesday as authorities said he was becoming increasingly agitated in the days leading up to the rampage and expressing disturbing behavior online. Kimbrady Carriker, 40, was charged with five counts of murder and other charges in the shooting that killed five people, prosecutors said.

The suspect was "exhibiting abnormal behavior for quite a while," Assistant District Attorney Joanne Pescatore said during a news conference Wednesday. The suspect lived in a house with seven other people, Assistant District Attorney Robert Wainwright told reporters.

"They thought he was getting more and more agitated as the days were passing," Pescatore said, "and their way of dealing with it was just to avoid it and not interfere with him even though they all lived in the same house."

Pescatore said the housemates told investigators it had become "the norm" for the suspect to wear his bulletproof vest and have guns in the house.

"I'm not blaming anybody, but if anybody out there has such a situation as this, maybe, maybe, just call, call somebody … and maybe he could have gotten help before this became what it did," Pescatore said.

Philadelphia Sheriff Rochelle Bilal said "disturbing messages" were found on a social media page belonging to the suspect. Bilal and prosecutors didn't provide additional details about the messages, but they urged people, in general, to report concerning behavior online to authorities.

"Let us use this opportunity to reexamine social media posts we may see that mentions harming someone or suggests extreme activities," Bilal said. "…They are letting people know what they are about to do, and that is on all of us to not sit silent."

Asa Khalif, a member of District Attorney Larry Krasner's LGBTQ+ Advisory Committee, told reporters that pictures of the suspect were being used to attack transgender people online. Khalif said the suspect has identified himself only as male, not as transgender.

"The language that is spewed out by the conservative press is violent and is dangerous and is targeting trans women of color," Khalif said. "It's rallying the community to be violent, and we're better than that."

During a court appearance Wednesday, the suspect was denied bail, and a preliminary hearing in the case was scheduled for July 24, CBS News Philadelphia reported.

In addition to the murder counts, the suspect was also charged with attempted murder and aggravated assault, a spokeswoman for Krasner said in a statement to CBS News.

Authorities on Tuesday identified the slain victims as Daujan Brown, 15; Lashyd Merritt, 20; Ralph Moralis, 59; Dymir Stanton, 29; and Joseph Wamah Jr., 31. Most of the victims died after being rushed to a hospital following Monday night's rampage in the city's Kingsessing area. Wamah was found with multiple gunshot wounds in a home hours later and pronounced dead.

"So far as we know, this defendant did not know any of the victims," Krasner told CBS News in an interview. "There was no dispute between him and any of the victims."

A 33-year-old woman and her twin 2-year-old boys were hurt during the shooting, officials said. The woman was driving as her car came under fire, and one of the boys in the back seat was shot four times in the legs, according to Wainwright, the assistant district attorney, and police. The other boy and the woman were hurt by shattered glass, police said.

The woman and the two boys were in stable condition at a hospital, police said Wednesday morning. The woman's 10-year-old daughter, who was sitting in the front passenger seat, wasn't hurt, Wainwright said.

A 13-year-old boy who wasn't in the vehicle was shot twice in the legs and was also in stable condition, officials said.

Police arrested the suspect after a chase, and he was wearing a bulletproof vest and a ski mask, officials said. The suspect was armed with an AR-15 rifle and a 9 mm ghost gun that's not traceable, Wainwright said. Investigators found a .380-caliber handgun at his home.

Krasner told reporters at the news conference that authorities were investigating how the suspect obtained the weapons. "Everything about his record suggests that these were obtained illegally," Krasner said.

Remembrance ceremonies were held in Kingsessing for the victims Tuesday. Merritt's girlfriend told CBS News Philadelphia that he was out getting something to eat when the shooting started.

"To get his life cut short like this, that's not fair," Breyana Burnett told the station. "…He didn't do anything at all to deserve this. I can't even imagine — I can't still face the fact that he's gone."

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• Shooting
• Philadelphia

Alex Sundby

Alex Sundby is a senior editor for CBSNews.com

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