Del Mar is safe.
If the analysis you are looking at is based on per capita, then the statistics can be easily skewed. Del Mar has a population of around 4500 people. Twenty miles north, Oceanside as an example has a population of around 161,000 people.
If you go to http://www.sandiego.gov/police/stats/
, they have crime rate calculations based on per 1,000 population. So if a bank is robbed in Del Mar and in Oceanside on the same day, it can appear that based on the population of each city, 1/4500 and 1/161000 - Del Mar has a higher bank robbery rate. But that is furthest from the truth. The two cities don't even compare.
You are wise to come to forums like this to ask because local businesses, realtors, and community citizens will give you the best and most accurate answers to your questions because we live here!
If you liked my answer, please vote it the best. Have a great day and come visit Del Mar. It is a beautiful beach city.