Here are some numbers which will either ease your mind or make you think twice, depending on your tolerance for city living:
Within the area of Alamitons Ave to Junipero, and 7th to the beach, in the last 6 months these are the incidents reported (roughly):
2 murders (both up by 6th and 7th streets, a third one just outside of this area)
around 5 dozen assaults (a half dozen on East Broadway)
about 3 dozen registered sex offenders live in that area
and about 100 burgleries and breaking and entries
I get this information from the website: crimereports.com--so you can check it out for yourself (be sure to adjust your seach to 6 months and not just one week).
So this is definitely not a place you want to let your gal take the dog out for a walk in the evening by herself. I don't think it is uncommonly dangerous for city living, but it is not unusually safe either. If you use common sense, lock your doors, stay out of situations that make you vulnerable and keep your wits about you, you should be okay. For a year or two during college it might be okay--and it definitely has its appeal: neatby beach, great weather, lots to do.
Okay, good luck, whatever you decide.