Three days after a 34-year-old woman was killed by gunfire in Brooklyn as she picked up her child after school, detectives arrested the accused gunman, his brother and a half-brother, the police said on Tuesday.
Police Commissioner Raymond W. Kelly said that Andrew Lopez, 18, and two others were taken into custody on Monday by detectives at a home in eastern Queens.
Investigators believe that Mr. Lopez, who was part of a loose-knit group of youths who live at 1800 Pitkin Avenue, was the person who opened fire Friday on another group of youths who live in a public housing project. The two groups were fighting outside Public School 298, on Watkins Street in Brownsville, just before the shooting, at about 2:30 p.m., the police said.
At least 12 shots were fired, the police said, and the woman, Zurana Horton, tried to shield several children who were in the area. Ms. Horton was fatally struck in the chest, the police said.
Cheyanne McKnight, 11, was grazed in the right cheek by a bullet, and another woman, Unique Armstead, 31, was shot in the left arm.
Crime scene investigators found seven shell casings from a semiautomatic pistol atop the building at 1800 Pitkin Avenue, where the police said Mr. Lopez fired from, and five more on the sidewalk in front of it. An investigation led the police to an apartment in Queens, where, on Monday night, they arrested Mr. Lopez, his brother Kristian Lopez, 17, and his half-brother Jonathan Carrasquillo, 22, the police said.
The police said that Andrew Lopez made statements implicating himself in the homicide, and was charged with second-degree murder, two counts of first-degree assault and other crimes. Detectives are still searching for the murder weapon, the police said.
On Friday, Mr. Lopez and his half-brothers were facing off outside the school with a group from a public housing project called the Howard Houses, the police said. “There is a rivalry between the young men, who live in the Howard Houses and these guys who live at 1800 Pitkin,” said Paul J. Browne, the chief spokesman for the Police Department.
At one point, Mr. Carrasquillo told Andrew Lopez to go get a gun, the police said. Detectives believe he went to the roof of 1800 Pitkin Avenue and opened fire on the rival group, the police said. No one in the rival group was believed to have been shot, the police said.
O’Neil Vaughan, 42, who has custody of five children he fathered with Ms. Horton, said the news of an arrest left him feeling conflicted.
“I’m glad they caught someone, that makes me feel happy,” Mr. Vaughan said. “But really it doesn’t help that much. We’re all devastated here. I lost somebody I care about, and my kids lost their mother.”
On Tuesday afternoon, about 20 people gathered outside the building where Ms. Horton lived, on Dumont Avenue, for a vigil that was planned before detectives announced the arrests.
When told of the developments, Antoinette Robinson, 42, who said she had lived in Ms. Horton’s building for a few years, said: “Hallelujah. Yes, Lord.”
She stood with others just outside the door to Ms. Horton’s apartment, where candles and a wreath had been placed. A piece of white posterboard was taped to the wall, with the names of 12 people who those gathered said represented the 12 children Ms. Horton had left behind.
Ms. Robinson said that since the shooting, she had worried that no police action would show criminals that they could get away with violence.
“This arrest shows that they can’t,” she said.
A friend of Ms. Horton’s, Valencia Mealy, 32, said she still felt unsafe in the neighborhood, which is one of the more crime-plagued areas of the city.
“The cops can’t protect everybody,” she said.