Authorities are considering at least two charges against the widow of the Orlando shooter, ABC News reports.
Little by little, details have begun to emerge about 30-year-old Noor Zahi Salman, who grew up in the small suburb of Rodeo, California, tucked in the dry hills near the oil refineries 25 miles northeast of San Francisco.
Her romance with Omar Mateen - security guard, bodybuilder and devout Muslim - began online, according to a neighbor, and they were married on Sept. 29, 2011, near her hometown, according to public records. The couple has a 3-year-old son.
Early Sunday, the 29-year-old Mateen opened fire at a gay nightclub in Orlando, Florida, leaving 49 people dead and 53 wounded.
— ABC News (@ABC) June 16, 2016
Authorities believe Mateen's wife knew about the plot ahead of time, said an official who was briefed on the progress of the case but insisted on anonymity to discuss a continuing investigation.
Three people identifying themselves as FBI agents visited Salman's childhood home in Rodeo on Tuesday and spoke with her mother, said Jessie Rojas, a next-door neighbor.
In Fort Pierce, Florida, where Salman and Mateen lived, Salman made a brief visit to their first-floor apartment late Monday, escorted by police and her brother-in-law. Her father-in-law said she came to retrieve clothing. She did not speak with reporters. She has otherwise been in seclusion.
According to marriage documents on file in the Contra Costa County Recorder's office, Salman was born in the United States while her parents' birthplaces were listed as "Palestine."
It's unclear when her parents, who served as witnesses for the wedding, came to the United States, but their naturalization papers allowing them to stay in the country were approved in 1984.
No one answered the door at the Salman home Tuesday, but neighbors who know the 2004 graduate of John Swett High School in nearby Crockett said they find it hard to believe she had anything to do with the massacre.
Jasbinder Chahal, who has lived across the street from Salman's childhood home for the last 15 years, said Salman is "very nice...not the smartest, but she was beautiful.
"You know, some kids after high school, they open up the box and the world is theirs. She was inside the box, just pack it up and get married," said Chahal.
"They had a small wedding and took lots of pictures here at the house," said Chahal. The marriage license says the ceremony took place in Hercules, California, and that an imam officiated.
Of Mateen, Chahal said, "He was shorter than her and did not seem very friendly."
Chahal said Salman's mother, Ekbal Salman, was deeply upset when she visited her Monday night and said she feared for the safety of her daughter and grandson.
Salman's parents tried to shelter their four girls as they grew up.
"Noor never played in the street, and the girls were never allowed to drive," Chahal said.
The neighbor quoted Salman's mother as saying Mateen also kept her daughter from driving, until he recently allowed her to take a test to get her driver's license.
Salman's marriage to Mateen was her second, said Chahal. Mateen had previously been married as well.
Her first marriage had been arranged in the Palestinian Territories by her parents, said Chahal, adding that the union did not work out.
"He was in Chicago and they were living there, but they were not married long," Chahal said. "They had cultural differences since she grew up here and was American."
Mateen had met his first wife, Sitora Yusufiy, online, too. They married in 2009 after a whirlwind romance.
Yusufiy, who immigrated to the United States from Uzbekistan, has told reporters that Mateen was mentally unstable and abusive during their brief relationship.
She said she knew quickly that the marriage had been a mistake and she left him a few months later. The couple didn't divorce, though, until June 21, 2011 - just three months before Mateen married Salman.
On one of her sister's Facebook pages - next to a family photo - there is a box with the words: "Solidarity with Gaza."
Salman rarely came home to visit after she married because Mateen would not let her, Chahal said. She quoted Salman's mother telling her that Mateen even tried to keep the daughter from traveling home to see her father when he was sick.
The younger Salman managed to scrape together the money to visit before her father died in a local hospital, Chahal said.
Associated Press writers Russ Bynum and Mike Schneider in Florida and AP researcher Rhonda Shafner in New York contributed to this report.