They just don't pay attention to news that doesn't support their world view. My in-laws claim you have no way of knowing who the people actually we're, but I'd bet money they have no idea more than a handful of people have been arrested.
I went to the Smithsonian with these same in-laws, went to the fossil area. My MIL said "these are all artist concepts, right?" I told her no these were all real, and the sign says where and when they were found. A few minutes later they left the area to go look at landscape photography. Basically the same as anything negative about Republicans, they see something that might be counter to their beliefs and they just ignore it.