“Colleges seem like idyllic and secure places,” Reader’s Digest says in its March issue, “but ivy-covered walls can’t keep out every bad element.”

In a special feature, “Is Your College Student Safe at School?,” the magazine ranks colleges’ crime rates and grades their campus safety.

It offers several examples of safety breaches, including robberies at San Jose State University and the University of Cincinnati, and praises some institutions for their “best practices,” like the University of Kentucky for its use of nontoxic theatrical smoke in fire drills.

The rankings, of 285 colleges in an Excel spreadsheet, are based on statistics from the U.S. Department of Education. Sweet Briar College and the University of Wisconsin were the lowest of the low-crime campuses, and the University of Virginia and Butler University were the highest of the high. Reader’s Digest looked at the number of crimes per student in 2004 and 2005 and weighed murder and rape more heavily than burglary and theft.

Wisconsin, with more than 40,000 students, reported no crimes in those two years, while Butler, with fewer than 5,000 students, reported a murder on its campus in 2004.

The magazine also conducted a campus-safety survey, asking 135 colleges whether they had, for example, an “emergency lock-down plan” and security cameras in their parking lots. The Johns Hopkins and Northeastern Universities topped the list of institutions with A grades, and Iowa State University and Principia College were at the low end of the C list. (No colleges received D’s or F’s.)

Principia, a 500-student institution in rural Illinois, fared poorly because it lacked, among other things, dormitory rooms with peepholes and a full-time campus police force. —Sara Lipka

Correction: This article originally identified Washington and Lee University and the University of Idaho as the lowest-crime campuses in the Reader’s Digest rankings. Those institutions actually rank 13th and 14th.