As Kenya struggles with rising violent crime, BBC Africa Eye follows one former criminal as he tries to persuade men to turn in their illegal firearms, one gun at a time.

“The worst thing I ever did was to kill. I killed a man,” the young man says after agreeing to be filmed on condition of anonymity.

“I did not feel anything, because I was high on drugs. I felt like I had killed a fly.”

Samuel, which is not his real name, is in Kisumu on the edge of Lake Victoria in the west of Kenya, to meet King Kafu, a former convict who now helps people get away from crime.

He is visibly nervous. He has an AK47 in a hidden location that he now wants to hand in to the police.

Asked why, he says: “A day will come when my family won’t have anything to eat. They will get hurt eventually.

“If I go and mess around, and then get shot, no-one will be there to take care of my family. So I decided, from my heart, let me return this thing.”

Figures from the Kenya National Bureau of Statistics show violent robberies increased by almost 20% last year.

Illegal firearms are smuggled into the country through its porous borders, making Kenya’s civilian possession of weapons unrivalled in East Africa, according to the Institute of Security Studies.

The latest figures from the Small Arms Survey, which tracks global weapons trends, suggest there are some 750,000 firearms in civilian hands in Kenya. That is more than the army and police combined.

Kafu acts as a middleman between people who want to hand in their guns and the police.

He was 15 when he first got into crime. It started with snatching people’s bags, but then he moved on to armed robberies.

In 2003, he was sentenced to four years in prison for robbery.

Samuel had contacted him on Instagram asking for help. Kafu spoke to the local police in Kisumu and they agreed to accept Samuel’s gun, promising he would not be investigated in line with a well-established amnesty programme.

But when it was time to meet up again with the AK47, Samuel did not show up.

Kafu, now 40, is a presenter on Ghetto Radio, a station popular among young people in the slum areas of the capital, Nairobi, and uses his platform to speak out against gun violence.

“Upon my release, I discovered many of my friends who were involved in crime had met tragic ends, most of them dying as a result of their criminal lifestyles,” he says.

It was this that made him turn his life around.

“No-one is born a thief. But even if the youths don’t have work, we are telling them that crime is not good. People should return their illegal guns to the government,” he says.

In the last 20 years the Kenyan government has used amnesties as a way of controlling gun crime, promising immunity to those who surrender their weapons.

Thousands of guns have been handed in to the authorities. But this is a tiny fraction of the illegal firearms in circulation.

One criminal told BBC Africa Eye that acquiring a gun in Kenya was easy. He said he could buy one for 40,000 Kenyan shillings ($300; £240).

Kafu says people willing to hand over their illegal firearms to the authorities fear they might become a target themselves.

The police have been accused of being involved in extra-judicial killings. Kenyan charity Missing Voices says more than 800 people died at the hands of officers in the last five years. The majority of them were poor young men.

In Nairobi, BBC Africa Eye goes with Kafu to meet another man, who we are calling John, willing to give up his gun.

“I am ready to return it. You go and kill someone. You will spend the money you get for it within three months, but you have shed someone’s blood. You have hurt someone and been left with the guilt. That life is trouble.”

John’s biggest fear of going to the police was that something would happen to him.

He describes what happened to a friend who confided in an elder in the community that he wanted to surrender two guns. He was picked up by the police and then found in a mortuary a week later.

“The problem is trusting who to tell, how to hand it in,” he says.

There have been widespread allegations of Kenyan police hiring and selling firearms and ammunition to criminals. BBC Africa Eye put this claim to the police, but they did not respond.

Kafu called the local police chief to reassure the man about his safety and a few days later they went to the police station together with the gun.

The officer checked the serial number on the weapon and it had a KP mark which is short for Kenyan Police.

At a police press conference announcing the return of the weapon, Kafu made a public statement to make sure the police repeated their commitment to keeping these men safe.

“I want the government to be clear with the youth. When they return these things, will they be disappeared or supported? I am asking the government to cooperate. These youths want to be shown some love.”

This alone will not stop violent gun crime in Kenya, but Kafu says it’s a start. Criminals trust him, he says, and hopes he can encourage more people to surrender their weapons without fear of retribution.

"We are trying to fight for these youths," says Kafu.