There is nothing wrong with knives, swords, etc., in checked baggage. Your bag will not be opened because of suspecions surrounding the knife if it is spotted by baggage screening.
Your bag may be opened if something in the bag resembles an undeclared gun or an explosive device.
If, for example, your cell phone was to sit in an exact relationship to your camcorder battery such that in the fuzzy, two-dimensional x-ray, the might resemble a gun, your bag might get opened for inspection. If the inspector discovered your knife, there would be no problem relating to the knife. There is nothing wrong with the knife being in your checked baggage. The inspector would see the cellphone and camera battery and laugh and tell his college, "False alarm! It's just a cellphone and an camcorder battery sitting near each other." And that would be that.
There is, of course, some concern about employee theft. The inspector might pocket your knife, or your cellphone or camera battery for that matter. The TSA hasn't thoroughly addressed this issue.
My advice is to take some digital pictures as you pack your bag. Then, close your bag with some sort of seal that will have to be broken to open it. A self-adhesive mailing label with your signature on it applied over the latch would be just fine. If, when you pick up your bag, your seal is not intact, do not open the bag but proceed immediately to the airlines baggage office and insist that they watch as you inventory your bag.