The inquiry into the bombings continued, even after one of the brothers suspected of setting off the blasts was killed on Friday, and the other captured. Investigators sought to discover where the brothers got the small arsenal of weapons they used, whether they had any help or were operating in league with anyone, and what motivated the deadly attacks. Tamerlan Tsarnaev, 26, was killed after a shootout with the police in Watertown, Mass., early Friday, and his brother, Dzhokhar Tsarnaev, 19, was captured that night in Watertown and now lies grievously wounded in a Boston hospital bed. Law enforcement officials said the two men, of Chechen descent, also killed a campus police officer, carjacked a sport utility vehicle and critically wounded a transit police officer. Prosecutors have been drafting charges against Mr. Tsarnaev for two days, according to officials, who initially said on Saturday and on Sunday that their filing could be imminent. While officials said the investigation had continued to develop new evidence, it was unclear what caused the delay and whether a criminal complaint would be announced on Monday. A memorial for Sean A. Collier, 26, the Massachusetts Institute of Technology patrol officer who law enforcement officials believe was shot dead in his patrol car Thursday night by the Tsarnaev brothers, was being planned for Wednesday, a university official said. On Monday morning, hundreds of mourners attended a funeral at St. Joseph Church in Medford for Krystle Campbell, the 29-year-old restaurant manager killed near the finish line of the marathon, a race she tried to see every year. The funeral was attended by her friends and relatives, as well as Gov. Deval Patrick and Representative Edward J. Markey. The mourners filed into the church as a single bell tolled. An overflow crowd lined the block. Julie Dziamba, 21, who had worked at a restaurant called the Summer Shack where Ms. Campbell had been a manager, traveled from New London, N.H., to pay her respects. “She always had a smile on her face,” Ms. Dziamba said, “even if she was mad at us for not cleaning up or getting things done on time.” The goodbyes to Ms. Campbell began Sunday. As Melanie Fitzemeyer, who baby-sat for Ms. Campbell two decades ago, walked to her wake Sunday along with hundreds of others, she took off her jacket and rolled up her sleeve. Incised on her arm was a two-line tattoo she had gotten the night before, at a parlor owned by one of Ms. Campbell’s cousins. “Boston Strong,” the top line read in black letters scored into the length of her forearm, the surrounding skin still pink and tender. “1983 Krystle 2013,” read the bottom. Ms. Fitzemeyer, 39, knew her longer than most, and remembered her as an exuberant child. “She liked to paint and color and make things,” she said. Some of the people wounded in the blasts remained in the hospital. A 7-year-old girl with multiple leg injuries was in critical condition at Boston Children’s Hospital on Monday morning, along with an 11-year-old boy with a leg injury who was listed in fair condition, the hospital said in a statement. Eight other patients have been discharged, the hospital said. Reassurance seemed to be the message from top city and state officials on the Sunday news shows. Mayor Thomas M. Menino said that what he knew suggested that the two brothers suspected of carrying out the attack had operated by themselves. “All of the information that I have, they acted alone,” he said on “This Week” on ABC. The danger has passed, Governor Patrick said on “Face the Nation” on CBS. “The immediate threat, I think all of law enforcement feels, is over, based on the information we have,” he said. “And that is a good thing, and you can feel the relief at home here.” Mayor Menino and Governor Patrick called on everyone in the state to come together for a moment of silence at 2:50 p.m. Monday — precisely one week after the bombings. That will be followed by the ringing of bells across Boston and the commonwealth. On Monday night at Boston University, students and faculty and staff members will gather on campus in honor of Lu Lingzi, 23, the Chinese graduate student who was killed in the bombing. “We will remember her and everything good that a bright, ambitious, and engaging student represents in our community, and, hopefully, speak about the values that make our community strong, even under such terrible circumstances,” Robert A. Brown, the president of the university, wrote in an e-mail announcing the gathering. The fourth victim, Martin Richard, 8, was mourned on Sunday in Dorchester at the church attended by his family. There were signs that the Boston area was returning to normal. Late Sunday afternoon, Mayor Menino briefed reporters about a five-phase plan to reopen the area where the attack occurred. It will involve decontamination, structural building assessments and debris removal. Newbury Street, the busy retail thoroughfare that runs parallel to Boylston Street, where the blasts took place, was bustling on Sunday, with visitors clutching shopping bags and relaxing in restaurants. But they were also drawn by the hundreds to gaze over the metal barriers cordoning off the six blocks around the marathon’s finish line. “It’s been really eerie,” said Calla Gillies, a 24-year-old real estate agent who lives inside the area, which she can gain access to with proof of residence. “We’re just still as scared because it’s empty. It feels like the marathon was yesterday.” Richard A. Oppel Jr. reported from Boston, and Michael Cooper from New York. Reporting was contributed by William K. Rashbaum from New York and Jess Bidgood from Boston.