The library's books, CDs, DVDs and other materials are free, but they're not for the taking.

"It's sort of the dark side of librarianship," Natrona County Public Library director Bill Nelson said Monday.

People still steal stuff even though anyone with a library card can check out nearly anything, even though individual donors and county taxes pay for the materials, and even though they know they're not supposed to, Nelson said.

So Nelson, public services librarian Kate Mutch and the library's board of directors are looking at ways to keep the materials secure without losing the personal touch and access that makes a library a library, he and Mutch said.

But finding information - one thing a library is all about - regarding theft remains elusive, Nelson said. "In library science, security is one of the most difficult issues to get your arms around."

Library theft data are sketchy everywhere, but Nelson figures people steal between 2 percent and 3 percent of the county library's 130,000 items each year from the main branch at 307 E. Second St.

While that's far less than some libraries that report upwards of a 20 percent theft rate, in Natrona County that still amounts to between 2,600 and 3,900 of your taxpayer-funded materials.

"It's not our material," Nelson said. "It's the people's materials."

Last week, Nelson applied his engineering skills to library theft and drew a fluid dynamics picture of what goes in and out of a library.

Purchased materials and public and private donations go into a library.

Checked-out and returned items are neutral.

It's the other outgoing categories that become problematic.

Last year, the library hired Unique Management Systems of Bloomington, Ind., to handle problems with items that fail to return, Nelson said.

If someone doesn't return an item, UMS will send that person a letter to tell them how much they owe, then another letter, and then follow with a phone call, he said.

If the library user doesn't get the hint, UMS then initiates collections actions, Nelson said.

If the materials are worth more than $500, the library will prosecute, he said.

The system is fully automatic, and has saved a lot of grief with library clerks, he said.

The library will augment its security with a new electronic security gate purchased with Optional One Percent No. 13 funds, he added.

UMS, Nelson said, also will collect money from library users who say they've lost the materials.

The library accounts for some of the other outgoing items in a "discard" category, when the staff remove materials from the collection because they're outdated, damaged or updated with new editions, he said.

After all these reasons for materials leaving, the library then must deal with theft, Nelson said.

Unlike some kinds of criminal behavior, Mutch said library thieves come from all social and economic backgrounds.

She also trains library workers to watch for people with sticky fingers, and even call police if they suspect theft, Mutch said.

Patrons often are willing to report suspicious behavior, Mutch said. "They've got their radar on."

Reporter Tom Morton can be reached at (307) 266-0592, or at Tom.Morton@casperstartribune.net.