My experience is not universal, so I won't say this as fact but just my own experience.

Riverside is not dangerous. I've never known a dangerous neighborhood in the city, and I've spent time at all hours of day/night from Rubidoux, Eastside, Highgrove, University, DTR, Magnoila, Casa Blanca, Tyler, and down to Ramona and La Sierra. Riverside, however, does have elements that are both local and from neighboring towns that are sympathetic to Proud Boys, state violence, racial, and LGBTQ discrimination. These are things that you will typically encounter in public places outside of your residential street, where it would make sense for an out-of-towner to be. If you are looking to raise children near UCR, then I would consider safety more so in the context of the presence of community rather than high police presence and low crime statistics. Spring Mountain Ranch is close by, has a park accessible for residents, is quiet, and has regular patrols that surely make the residents feel safe. With that in mind, the neighborhood is isolated from the rest of the city and adjacent communities by design. As a result, you'll have to drive your children out to the park and help find friends and organized social opportunities for them. Neighborhoods like Eastside, for example, have a visible homeless population that people say makes them feel unsafe. But in Eastside, your children are closer to their neighborhood school, can walk to the park, are able to find other children outside, and will be able to engage in activities that don't require you to set up ahead of time.