Well those brownstones are in Riverside, NJ.
As for Riverside CA check out Wikipedia:
"The three most gang-prone areas are the Casa Blanca, Eastside and Arlanza neighborhoods. Data collected by Project Bridge, an anti-gang program under the City of Riverside’s Park and Recreation Department, shows that the city of Riverside has experienced an increase in gang membership and gang activity since the early 1990s. In 1991, Riverside had approximately 82 gangs with 4,500 active gang members. More recent estimates indicate there are 86 gangs with 8,000 members. Reportedly 2,000 of these members are juveniles, while 10 of these gangs are primarily comprised of minors. The juvenile crime rates did drop dramatically between 1994 and 1997 for these areas. However, juvenile crime rates have exhibited a gradual and steady rise since 1998. In 2000, Casa Blanca, Arlanza and Eastside had crime rates of approximately 40, 18, and 30 per 1000 youths, respectively. Of these three areas, the Eastside’s problems are compounded by the highest unemployment rate in the City, 25.1%. The neighborhood also has the lowest educational attainment in the City, with 32% of the population having less than a 9th grade education. Project Bridge has provided comprehensive services to at-risk and gang-involved youth between the ages of 12 and 22 and their families in for over a decade. Since 1995, the program has served over 500 gang-involved youth with recent enrollment nearing 150 participants. Almost 50 percent of participant enrollment is generated from the Eastside." -Wikipedia.
Riverside CA gang task force website says:
"Since 1997, the number of gangs in Riverside County has grown from 223 to 341. The total gang membership has grown to an astounding 10,553 members countywide. During this same time frame, there was a significant increase in gang related crimes reported by Riverside County law enforcement agencies."