By Jessica Donati

KABUL (Reuters) - Blood is spattered around a thick blade in the back of a body hunched over on the ground, the head bowed and hands clutching a bag of white powder.

But this time the victim is a mannequin and gathered around in a spartan wood-paneled classroom in a run-down neighborhood on the outskirts of the Afghan capital are a dozen senior Afghan police, most in uniform but some in worn grey suits.

The detectives are being taught how to solve a crime by using physical evidence and witness statements, rather than by extracting a confession, perhaps with excessive force, as rights groups often complain.

"If the crime scene is like this we know the victim is already dead," says Mohammad Zahir, a grizzled veteran detective turned student at the Crime Scene Management College.

Overseeing the class at the back of the room are two uniformed members of the European Union's police mission in Afghanistan.

With pistols on their thighs and arm bands dotted with EU stars, the two are training their Afghan counterparts in advanced crime-scene analysis.

Zahir explained how he would go about collecting evidence at a murder scene, summing up the lesson he has learned that day.

"It's all through this evidence we can prove that the suspect is guilty. For example, we can say we found a bullet casing or a fingerprint that belonged to him at the scene," he said.

More than 800 students have passed through Kabul's school for detectives as Afghanistan's Western allies prepare to hand over full responsibility for security to the Afghan military and police by a 2014 withdrawal date.

"Everything we do has sustainability and transition in mind," says David Thomson, a British policeman who commands the college run by members of the EU's 350-strong international police team in Afghanistan, known as EUPOL.

"There's no point in us doing everything and then leaving."

CHALLENGING

Afghan instructors shadow the class to pick up the skills they will need to replace the Western officers when they withdraw. The day's crime scene management class involves a dozen students but many others peer in from a dusty yard.

Students are all fully trained police, some with decades of field experience, and almost all are men. There are a few women in the Afghan police, but most who succeed in joining tend to remain in support roles.

Although the college gets regular bomb threats and from time to time has been evacuated because of security alerts, teaching staff say threats have not dampened the appetite of the students to learn.

"What's most impressive about this group is they are challenging each others' ideas and from that they are growing," says Mick Serbatoio, an Australian instructor who has taught in other police academies around the world.

Some students don't just challenge their peers, they are also prepared to challenge their mentors.

An Afghan detective leading a student team bristles and erupts into a loud defense of his action when told by an Australian instructor that he has just walked over some foot prints that could be evidence.

An increasing number of so-called insider attacks by members of the Afghan security forces on Western advisers and soldiers has made many people edgy.

But the heated moment passes and all seem prepared to accept that evidence gathering is a crucial part of detective work.

"The crime scene is the key to solving cases," said Zahir.

(Editing by Rob Taylor and Robert Birsel)