SAN JOSE — With his shaggy white Jack Russell terrier trailing close behind, Warren Doleshel stopped his afternoon walk to peer into what looked like a giant block party inside a troubled alleyway known for gang activity.

“What is going on in there?” Doleshel asked Saturday. “Is this open to the public?”

The surprise reaction is expected. The Business Circle back alley, across from the Pink Poodle strip club, isn’t exactly a family-friendly site. But on Saturday, the alley was the site of a community event with music, games, food and art.

The Santa Clara County District Attorney’s Office, along with county Supervisor Ken Yeager, sponsored the event and paid for a $3,000 mural to be unveiled there. The three-hour block party in the Burbank district of San Jose attracted families and curious onlookers like Doleshel.

The idea, according to deputy district attorney Alisha Schoen, is for the community to “take back” the space at West San Carlos Street and South Bascom Avenue, which has been a magnet for illegal activity in recent years.

“We’d heard from neighbors that Business Circle was a hot spot for them,” Schoen said. “They were concerned about empty buildings, the burned bank building and potential criminal activity in the back alley.”

One of those vacant buildings, home of the old Bank of the West, will soon become the location of another adult business — Hustler Hollywood — drawing the ire of neighbors. The sex store retailer plans to open in October, with Hustler founder Larry Flynt scheduled to make an appearance.

On Saturday, dozens of children tossed around beanbags, painted a blank wall and played with a life-size Jenga game. They snacked on hot dogs and ice cream as police officers chatted with residents.

Doleshel, a pizza delivery driver, decided to stop and grab a snack. He said he thought the event was an innovative way to revitalize the troubled area.

“This has always been a rough neighborhood,” said Doleshel, 62. “You’d sometimes see a group of young people up to no good. This is a great thing, especially in an era that police are coming under scrutiny.”

Bruno Dezan, 57, an executive caterer to Apple CEO Tim Cook, agreed that the block party would help residents take ownership of their neighborhood. He lives on the other side of the alley.

“It helps to change the environment and attract different people,” Dezan said, watching his 6-year-old son, Matteo, play the Jenga game. “It’s been a fun day.”

Officials from the Greenbelt Alliance, a nonprofit that encourages community-friendly growth, said the site is home to a future “urban village,” San Jose’s vision for building walkable, transit-oriented communities. Greenbelt Alliance co-sponsored the event.

“We want to make sure the city grows in ways that benefit everyone,” said program director Matt Vander Sluis. “That means better parks, more green space, safe bike trails and walkways, homes that are affordable for all and improvements that reflect the rich culture of the place.”

The District Attorney’s Office sponsored a similar event on Scott Street in May. Schoen says her office plans to hold more block parties to promote community involvement.

Contact Ramona Giwargis at 408-920-5705. Follow her at Twitter.com/ramonagiwargis.