Here is a site to check on crime statistics.
Ask the owner to tell you about any crimes they know about nearby. Your best bet is to knock on the nearby neighbors' doors, introduce yourself and say you're thinking of buying that home, and ask them about the neighborhood. You'll learn a lot that way. Some may be true, some may be gossip, but you'll meet the neighbors (important) and get valuable data.
Some of 95125 is truly Willow Glen; some is borderline.
Always trust your gut. If it feels unsafe to you, don't over-analyze, just don't buy it.