Wow, these comments, based on who knows what supposition. If you're asking about "the Valley" then you're probably talking about the area around Valley Street between Dean St/Pleasant Valley Pkwy and Atwells. Beyond that, it's Olneyville. The converted mills in that area are pretty popular and there isn't much crime.

If you mean the "Valley" neighborhood as defined by the city as one of its 25 neighborhoods, then you can probably find crime statistics for the neighborhood. It doesn't seem like there are any commenters from the neighborhood on this thread.