That's a rimfire AR clone, but the lower reciever could be pre-ban and legal (which is probably why there was no warrant).
Look at the ejection port ... that is an AR with a .22lr insert bolt and .22lr mag. It is easily put back into 223/556 configuration. AND THERE IS NOTHING WRONG WITH THAT! The Bible says to raise up a child int he way that they should go ... teaching proper safety and handling of tools is part of raising up the child properly.