Although it's probably shocking, it's not exactly news. Since crime peaked in the early 1990s, it's been dropping year after year. From 1993 to 2017, for example, violent crime dropped 49%, according to the FBI numbers -- 74% according to the Bureau of Justice Statistics. Property crime has also dropped -- 50% according to the FBI and 69% (nice) according to the BJS. If it seems like those guys should be talking to each other a little more, the reason for the discrepancy is that crimes often don't get reported to the police (the source of the FBI numbers), but people are more likely to fess up to being a victim when the BJS calls.
So how can politicians go on TV and claim that the U.S. has become a free-for-all of criminal depravity? Well, we don't mean to blow your mind here, but often they're lying. Other times they're cherry-picking data, pointing to small, short-term upticks that are outliers in the long term. They do that because they know that scared people vote harder than relaxed people, and there's no better way to get votes from scared people than by promising to make the big bad monsters go away.
Never mind the fact that it doesn't appear to matter who's in charge; crime rates have kept going down regardless of whether Democrats or Republicans were in power at the time. The strategy works because people don't know that we're living in arguably the safest period of history ever, which is why poll after poll after poll shows that American fear of crime has stayed the same or even risen as actual crime plummets. Legally, we can't advise you to go unlock all your doors and put a "Come at me, burglars" sign on your front lawn, but we can't stop you either.