The latest figures from the FBI, Bureau of Justice Statistics and public health agencies show that among black youth, rates of robbery and serious property offenses are the lowest in more than 40 years. Rates of murder and rape are now lower than when nationwide crime statistics first appeared in 1965 — and those were far less complete than today’s. Assault rates are lower than when this crime statistic was expanded to include domestic violence and new offenses a quarter-century ago.

Violent and other criminal victimizations of young African-Americans have also plummeted to record lows, as have a host of other ills including unplanned pregnancy, drug abuse and school dropout rates. While the numbers remain considerably worse for blacks than for other groups, murder and violent crimes remain very rare events among African-Americans — and among youth in general.

We still don’t know the facts about the self-appointed neighborhood watch volunteer George Zimmerman’s killing of the black 17-year-old, who carried only candy and an iced tea. The point to ask is why authorities and the media regularly depict young African-Americans as cold and violent — a misrepresentation that leads to widespread fear toward black youth.

Zimmerman’s recorded conversation with the Sanford, Fla., 911 dispatcher specifically cited Trayvon’s youth and skin color as indicators of his potential criminal or drug-intoxicated threat.

But is that view of teenagers, especially African-Americans, unusual? Hardly. Some of those now deploring Zimmerman’s alleged murderous attack on Martin have contributed to the larger climate of race- and age-targeted fear.

Consider President Barack Obama’s past comments. It is true that he called the shooting a “tragedy” on Friday, adding, “I think we all have to do some soul-searching to figure out how does something like this happen.”

But during his 2008 campaign, Obama deplored African-Americans’ “epidemic of violence” that he blamed on an “entire generation of young men in our society.” In “The Audacity of Hope” and “Change We Can Believe In,” Obama connected “this generation” of young African-Americans to “violence” and “addiction” and fanned anxiety toward a host of supposedly new cultural dangers, including “teenagers hanging around on street corners.”

Obama, of course, is hardly alone. Media claims that modern black youth represent a new scourge of cold-eyed killers have been disturbingly routine. For example, Anderson Cooper’s “Deadly Lessons” program on CNN accused African-Americans of perpetrating “a growing culture of violence, especially among young people,” described by one commentator as “a generation of folks that do not value life.”

Certainly, no one is urging local citizens to track down and shoot black youths who appear in their neighborhoods, and it is highly unlikely that specific remarks incited Zimmerman to shoot.

It’s troubling, however, that the inflammatory words suggest that all young African-American males must be suspected of criminality, drug use or callous behavior — so much so that their presence could be seen as cause for concern, if not outright fear.

The issue is not that blacks do have higher murder rates. It is an elementary principle of tolerance that individual misbehaviors and disparate statistics on rare crimes do not justify harsh attacks on the entire class or generation of young black men.

For example, in Chicago in 1994, the worst year with the highest murder rate, 168 of every 100,000 black teens ages 15-19 died from homicide — a rate nearly 20 times higher than for white teens.

But even in this worst and most tragic situation, murder remained rare, less than two-tenths of 1 percent. It was far from being a behavior that characterized all black youth there — or anywhere else. Since the early 1990s, homicide deaths and arrests have plunged by 70 percent among black youth in Chicago and nationwide — making this generation even less deserving than past ones of being condemned for wanton killing.

Obama’s remarks betray an uncharacteristically careless disparagement of an entire class of people that contradicts his presidential goals of reason and tolerance. Indeed, it’s impossible to imagine Obama stigmatizing an entire adult group in society, such as middle-aged African-Americans or Chicago’s grown-ups for violence simply because, statistically, they suffer considerably higher arrest and victimization rates than, say, white teenagers, or Vermonters.

Why, then, is it acceptable to disparage all young African-Americans? Apparently because, unlike adult groups, youths lack the power to fight back against demeaning stereotypes.

A poignant and powerful way for Obama to commemorate Trayvon’s death could be to help try to reverse the climate of fear that now envelops young people — especially young black men.

Mike Males, senior researcher for the Center on Juvenile and Criminal Justice in San Francisco, is the author of “Teenage Sex and Pregnancy: Modern Myths, Unsexy Realities.”