The alleged gunman in Friday’s deadly shooting at Los Angeles International Airport texted his younger brother that he might harm himself and was apprehended with a note that said he “wanted to kill TSA,” according to authorities.

Paul A. Ciancia, 23, of Los Angeles, grew up in Pennsville, N.J., a small town on the Delaware River, located in the southwestern corner of the state. His father owned an auto-repair shop in the same city, and his mother, a Catholic-school teacher, died more than four years ago.

Pennsville Police Chief Allen Cummings, who has worked with the city’s police department for 23 years, said he has “never had trouble with anyone in that family.”

But on Friday afternoon, Ciancia’s father, also named Paul, called the chief. “Is this my son I’m looking at on TV?” Cummings remembers him asking.

Ciancia’s father had called earlier in the day about the text message to the brother, prompting Cummings to call the Los Angeles Police Department for a well-being check on Ciancia.

A timeline of events from the LAX TSA shooting

LAPD sent a patrol car, and officers there found two roommates, who said Ciancia seemed fine on Thursday but had not been seen Friday, Cummings said. “We didn’t put two and two together at that point, that’s for sure,” the chief said of the first conversation.

Ciancia was wounded during a shootout with police, but law-enforcement officials have said he survived the incident. He was in critical condition Friday night at UCLA Medical Center, according to authorities.

Ciancia’s note, found in a bag he was carrying, included anti-government rantings, but it made clear he did not want to hurt innocent bystanders, authorities said.

James Mincey, who said he lived with Ciancia in a Los Angeles apartment until February, told an ABC affiliate: “I’m absolutely shocked. I’m still trying to wrap my brain around it, because from knowing this guy, it just doesn’t make sense.”

Asked whether Ciancia ever talked about problems with the government, Mincey said: “No, he would always talk about documentaries he would watch about whatever, but there was never any kind of — about any hatred or hatred group or anything like that.”

Mincey said Ciancia told him over lunch last week that he planned on “going back to New Jersey, going to work for his dad, making amends with family problems and spending holidays with his family.”

Pennsville School District Superintendent Michael Brodik told the South Jersey Times that Ciancia did not attend Pennsville schools. A 2008 graduation list from Salesianum High School, a private school in nearby Wilmington, Del., includes a Paul Ciancia, according to the newspaper.

Josh Pagan, 17, who lives across the street from Ciancia’s Pennsville home, said the suspect worked in his father’s repair shop after school, according to the Philadelphia Inquirer. “You wouldn’t think someone like that would come out of a family like that,” he said, adding that it would make more sense to him that authorities had accused the wrong person.

Others who knew Ciancia in high school described him as quiet and shy, with no signs of violent tendencies. David Hamilton, who graduated with from Salesianum in 2008, told the Los Angeles Times that Ciancia “kept to himself and ate lunch alone a lot.”

“I really don’t remember any one person who was close to him,” Hamilton added. “In four years, I never heard a word out of his mouth.”

It is unclear why Ciancia moved from Pennsville. Residents describe their town as a sleepy bedroom community, where most of the people work in more populous areas of New Jersey and Delaware.

“All the people I’m close with have moved on and have careers out of state or something,” said Charity Jagielski, who was born in Pennsville but now lives in Lakeland, Fla. “The expectation is that you go to college.”

Sari Horwitz contributed to this report.