Authorities in western Iowa and Nebraska are investigating several bogus 100-dollar bills that turned up at local merchants. John Gutsmiedl, an agent at the Secret Service Bureau in Omaha, says the bills are fairly good quality, and a pen some clerks use to detect counterfeit money sometimes won’t work. Gutsmiedl says the pens mark some as counterfeit but sometimes indicate a “false mark” on notes that are genuine money. The agency doesn’t use that pen, but rather security features built into the bills to determine whether they’re counterfeit. Gutsmeidel says there are many security features built into U.S. currency, including a security thread. He says there is also color-shifting ink– which is the first thing you should look for on the newer notes. Down in a corner look for the denomination of the bill and see that number change color as you turn it this way and that. Also, a watermark in the paper will be missing in fakes. The agent says there are typically three different processes that are used to produce counterfeit money.Some use a big press almost like a newspaper’s printing press, some use an office-type color copy machine, but most nowdays use a computer and its scanner and color printer. Gutsmiedel says the fake bills currently in circulation were made by the computer process. And he has some advice to offer merchants, when it comes to identifying bills that may be bogus. He says merchants should look for all the features built into U.S. currency, “Because 99-percent of the counterfeits we see out there don’t have any of the security features that are ‘native’ to U.S. currency.” The agent says the phony hundreds showed up mostly at businesses along Interstate-80, indicating to the federal investigators that someone’s passing through the area, and spending the funny money where they can get away quickly. Gutsmeidel says they are exploring some leads in the case, but can’t say much more because it’s an active investigation.