require registration, don't require background checks or serial numbers and can be purchased easily via the web or out of magazines. here is what the santa monica police told us. >> you can buy legally certain parts, it's called an 80%, you can buy those parts and an under reseverer, the over and understander and put them together with a trigger group and manufacture your own gun with adjustments. in this particular case the weapon he ended up with was by definition would be illegal to possess here in the state of california. >> reporter: under federal law it's perfectly legal to own it if you don't sell it and it's for personal use. even though this man is considered unfit to own a gun, he was able to build one. >> thank you very much. this sunday, girl rising takes a look at the importance of education for girls around the world and afghanistan, more than half of girls are married