En Español.

One day after 24-year-old Aldo Troncoso was murdered in a shooting at 17th and Mission streets, his friends returned Sunday to tend to his memorial of photographs, flowers, candles and empty beer bottles. Balloons tied to the pole bobbed in the wind.

His girlfriend, who declined to talk, wrapped her hand around the telephone pole where a new photo of her boyfriend had been taped. “We used to kick it all the time,” she said to the image of the young man who went by the name of Trigger. Nearby, friends hung close, moving the candles in front of the memorial into the formation of a cross.

“We didn’t kick it,” said one young man about the victim. “I would just see him in the streets, you know, and say, ‘What’s up, bro?’”

Up and down Mission between 17th and 16th streets, life went on Sunday as it has for decades. A mixture of families out for lunch or shopping and residents from the single-room occupancy hotels filled the sidewalks. One long-time resident said the stretch had not changed since he was a child, when along with nearby Capp Street it was known as the “Ho Stroll.”

“There’s a lot of gang banging, a lot of prostitution,” said one law enforcement official who asked not to be identified. “I’m not surprised that violence has popped up there. And then you have the hipsters coming around to the nightspots. There’s a lot of people looking for drugs, so that all works well together. It makes for a thriving community.”

Since the beginning of the year, some 64 crimes have been reported within 500 feet of 17th and Mission, including 19 assaults, 7 arrests for drug- and alcohol-related charges and four crimes involving weapons, according to the San Francisco Police Department’s crime maps. Saturday’s homicide was the first this year in the Mission District.

Earlier this month, on Feb. 7, two men in a green car drove by the intersection at 7:30 a.m. and shot a young man. He was treated for non-life-threatening injuries and released. A shooting there on August 10 at 10 p.m. ended with three men injured.

Aldo Troncoso, 10.07.86-02.26.11

The street is considered Sureño territory, but criminal activity comes from elsewhere as well, said one long-time resident. “Some of the gang members do pimp some of the girls out there, and some of the gang members do sell drugs, and then you’ve got a big mix that shares turf.”

It’s unclear if Troncoso was a gang member, but he had some run-ins with the law as a minor, according to a source who asked not to be identified. His last incident as a juvenile occurred in April 2005, when he was 17 years old.

An officer at Mission District Station said Saturday night that there will be a lot more undercover officers in the area for the next few weeks. One source who used to work in community violence said that a whole system to prevent more violence kicks in when something like this happens. “The thing you want to do is prevent retaliation, and help the family,” he said.