Nearly 850 people are registered sex offenders in Tucson and 36 of those people live with in a mile of the University of Arizona.
One map, provided by the Arizona Department of Public safety, shows the offenders' homes.
One point on the map shows that 22 convicted offenders live together in a cluster of apartments.
On Monday thousands of students went back to school at the UA and many live in the neighborhoods near by.
But do they know their neighbors?
KGUN9 showed the map of offenders to students at the university and one student said she would be sure not to walk alone and would be more aware of her surroundings.
The University of Arizona Police Department recommends that students download the app called "Live Safe."
UAPD Sgt. Filbert Barrera says students can have their friends watch you walk home through the app.
"Live Safe" also can connect users with police dispatchers. Police warn students to always be aware of their surroundings.
There have not been any reported assaults in the neighborhoods involving registered sex offenders.
The map is a good tool for people who live around the area, but many offenders are listed as homeless.
UAPD reminds students that they can call officers for a ride at night if they are worried about their safety walking around campus.