While there have been problems with the safety and security of a handful of UD students, there is essentially nothing to worry about. Safety issues are not uncommon in a college atmosphere such as Newark, where alcohol and youth account for a good majority of the crime. UD is certainly no worse than any other large campus and, if you put a little effort into avoiding bad situations, you should come through college unscathed.
On a day-to-day basis, most students don't really worry about security. While it is always wise to keep an eye on your belongings, crime isn't a major focus. The number of muggings, attacks, and rapes has been quite high, with the result that students have been a little more aware of their actions. There are many safety features on campus that help get students from one point to another, but these same features sadly do not extend to off-campus locations. This weakness has been a major issue, as nearly half of all UD students live off campus, and UD has taken some steps to change it. No college is completely free of problems, but Newark is a small town that is relatively safe and secure.