"We are seeking a balance," Riordan said, "between aggressive prosecution . . . and enlightened enforcement."
"If this is going to help put more officers in the area, I'm all for it," said Jeanne Rowe, 82, a civic activist and an accountant who recently completed her 46th year of tax preparations. "If they need more help in doing their job, I'm all for it."
But not everyone is -- not by a long shot.
At community meetings this year, critics have complained that the injunction is heavy-handed and broad, criminalizing, in a sense, an entire community.
"What is going on here is very unjust. Just because people are scared does not make it right," said Luis Rodriguez, whose home is inside the injunction boundaries.
Rodriguez, 54, was a member of a South San Gabriel gang, an association that left him imprisoned and addicted to heroin.
He became a journalist, then a writer. He is the author of "Always Running," a memoir about his gang years and a cautionary tale for his son, which has sold more than 300,000 copies.
Rodriguez works with at-risk young men, some of whom have had association with gangs. Targeting them through law enforcement when there is no evidence that they have committed a specific crime, he said, shows a lack of imagination.
"If these kids are sitting around the park in Sylmar with nothing to do, that's because there is nothing for them to do," he said. "We can save these kids. But the way this thing is set up, if the gang doesn't get you, the police will."
Some residents have complained that property values could be hurt by a blanket declaration of gang activity. Kevin Godley, a real estate agent who sells houses in the area, noted that financial institutions often rely on agents to establish base prices -- and that agents are expected to list a gang injunction as a factor in assessing value.
"There will be a stigma," he said. "Even if it gets cleaned up, there will be a stigma."
The result is two strikingly different portraits of the same community.
In court documents filed to support the injunction, officials described a "reign of terror" perpetrated by the gang -- and a community where residents are "virtual prisoners in their own homes."
Many residents say that does not sound like the community where they live.
Sylmar Park, for instance, was described in the documents as having been seized by San Fer -- "claimed," the documents state, "as theirs."
But this summer, 60 children a day attended camp there, without incident. There are year-round programs -- the usual mix of soccer, softball and other sports leagues, many with waiting lists.
"This is a nice community," said Los Angeles City Councilman Richard Alarcon. "It has been cast as a war zone."
Caught in the middle of two competing images, residents say, are young men, many of whom now try to avoid simply walking down the street.
Back at Daniel's house, his grandmother said she began lighting candles and praying for him every night after his latest encounter with the police.
Every time it happens, she said, it seems to fuel his anger.
Even before the spray-painting incident, an officer stopped him for riding his bike without a helmet. The officer pulled up Daniel's shirt to see if he had tattoos, then asked him if he was a meth addict because of his acne.
"He has acne," his grandmother said, "because he is 15 and eats too much fast food."
After that encounter, Daniel shaved his head -- knowing that it made him look more like a gang member, making it more likely that he might be stopped by police again.
At his school, there are kids from other nearby communities who associate with different gangs. What if they learn that he has been targeted through the injunction? Would Daniel, his grandmother asked, then join the gang to protect himself -- joining, in effect, because he was accused of being in one?
She smiled, realizing that she was talking in circles.
"Do you know that when someone gets pregnant here, we pray that it is a girl?" she said quietly. "That's because boys here go to war."