1971年，一个叫D.B. Cooper的人，劫持了美国西北航空公司的一架从Portland飞往Seattle的飞机，在收到20万美元的赎金和四个降落伞后，命令飞机飞往墨西哥。黑夜中，飞机飞到华盛顿州的西南部，他打开飞机尾部的门，带着两个降落伞，跳下飞机，消失在茫茫的雨夜中，从此杳无音信。1980年，一个男孩在哥伦比亚河边发现了被偷去的5800美元，钱已经很破烂了，都是二十美元一捆的票子。

Cooper是死是活，一直是个迷。最近FBI公布了Cooper的照片，下面是CNN今天关于这件事的报道：

The FBI is making a new stab at identifying mysterious skyjacker D.B. Cooper, who bailed out of an airliner in 1971 and vanished.

The FBI this week released new details that the agency hopes will jog someone's memory.

The man calling himself Dan Cooper, also known as D.B. Cooper, boarded a Northwest flight in Portland for a flight to Seattle on the night of November 24, 1971, and commandeered the plane, claiming he had dynamite.

In Seattle, he demanded and got $200,000 and four parachutes and demanded to be flown to Mexico. Somewhere over southwestern Washington, he jumped out the plane's tail exit with two of the chutes.

On Monday, the FBI released drawings that it said probably are close to what Cooper looked like, along with a map of areas where Cooper might have landed.

"Who was Cooper? Did he survive the jump? We're providing new information and pictures and asking for your help in solving the case," the FBI said in a statement.

The FBI said that while Cooper was originally thought to have been an experienced jumper, it has since concluded that was wrong and that he almost certainly didn't survive the jump in the dark and rain. He hadn't specified a route for the plane to fly and had no way of knowing where he was when he went out the exit.

"Diving into the wilderness without a plan, without the right equipment, in such terrible conditions, he probably never even got his chute open," Seattle-based agent Larry Carr said.

He also didn't notice that his reserve chute was intended only for training and had been sewn shut.

Several people have claimed to be Cooper over the years but were dismissed on the basis of physical descriptions, parachuting experience and, later, by DNA evidence recovered in 2001 from the cheap tie the skyjacker left on the plane.

In 1980, a boy walking near the Columbia River found $5,800 of the stolen money, in tattered $20 bills.

"Maybe a hydrologist can use the latest technology to trace the $5,800 in ransom money found in 1980 to where Cooper landed upstream," Carr said. "Or maybe someone just remembers that odd uncle."