I don't know whether crime is up or down. A lot of places have deliberately fudged the numbers in various ways to make it appear crime is down. Reportedly Chicago fudged their numbers so much the FBI refuses to use them.
A popular meme is that people are so much more evil and corrupt that fraud must be obscuring the lastly increased crime rates people who buy into this meme 'know is there'.
I really think there is a fairly large drop-off in crime rates based on two things:
Demographics, we are an aging nation and crime, particularly violent crime, is a young man's game. Most crime is committed by males who are 15 to 30. Fewer males in that group pretty much defines and explains a lower crime rate.
I also, as a personal bias based on studying history, I really doubt that all other things being equal, people have become more evil and corrupt over time. Yes, it is entirely likely that some cities and localities are obscuring their crime rates. But it is also pretty clear that many places were doing the same thing a decades ago, and pretty much forever.
Until the 60s a certain Florida small town was claiming it essentially had no crime. Sure, the mayor's boys were hellions who got drunk, beat people up, even burnt down a house with people inside but .... that wasn't really crime. Boys will be boys and youthful enthusiasm. And yes, there was that accusation of rape but the girl was not selective with her favors ... And the sailors from the navy base one county over would drive in to party and raise hell but no real crimes. We have a nice, safe town here full of honest, God fearing people. We work hard to keep it that way so the tourists feel safe.
Read the book "In Cold Blood" by Truman Capote. It relates a true story of the murder of a family in 1959. It sold well in part because the idea of a stranger going into a house and killing a family was relatively new. It caught the public imagination and inspired may other stories.
From:http://www.alternet.org/books/145819/ayn_rand,_hugely_popular_author_and_inspiration_to_right-wing_leaders,_was_a_big_admirer_o%3Cbr%3Ef_serial_killers?page=1
"Back in the late 1920s, as Ayn Rand was working out her philosophy, she became enthralled by a real-life American serial killer, William Edward Hickman, whose gruesome, sadistic dismemberment of 12-year-old girl named Marion Parker in 1927 shocked the nation. Rand filled her early notebooks with worshipful praise of Hickman. According to biographer Jennifer Burns, author of Goddess of the Market, Rand was so smitten with Hickman that she modeled her first literary creation -- Danny Renahan, the protagonist of her unfinished first novel, The Little Street -- on him."
(I never like Rand and this did nothing to make me like her more.)
Then we can go to the Bath School Disaster: In a nutshell
1927 -- US: Bath, Michigan School Disaster. Andrew Kehoe, seeking revenge against the community for taxes imposed on his farm to pay for a new school, set off a TNT bomb in the school, killing 43 people, including 39 grade-school children. After the explosion, Kehoe killed his wife, then drove his truck back, loaded with dynamite & nails, to the school, & set it off, killing himself & the school superintendent.
So we have a family annihilation attack in 1959, a kidnapper and serial killer and a anti-tax bomber in 1027. These were all big news at the time but the popular view, fueled by a steady drumbeat of fictional mass murderers every night on crime shows, the feeling is that murder is much more common now.