Both of these neighborhoods proper have crime rates that are way, way below the statewide average. And consider that CT on average is one of the 3 or 4 safest states in the US.

Most of the crime in nearby areas would be in areas with low income housing (like, in adjacent neighborhoods - for example if you are biking from Spring Glen to downtown New Haven you go through Newhallville on the canal trail a few blocks away, and that is probably the most disadvantaged neighborhood in the area) or in the big commercial areas (which just have crime incidents because of the overall amount of activity). For example many people have been carjacked in the Stop and Shop and other large shopping plazas next to Spring Glen. The neighborhood itself is very safe though, and given the number of people shopping in those areas, statistically your risk of being a victim is very small.