Mlungisi Zondi was 18 years old when he was sentenced to life imprisonment.
He thought his life was over when he contracted HIV after being sexually assaulted in jail.
Mlungisi was so devastated he decided to kill himself.
But after two failed suicide attempts, he realised he had a purpose to serve and a reason to exist.
Today the 34-year-old has turned his life around.
He's a youth coach, HIV and anti-drug activist, and he's published a book about his experiences.
This is his story.
"I was born in eSikhawini in the northern KwaZulu-Natal (KZN).
I was always a troublesome child and hung around kids that were older than me.
By 11 I was doing drugs, most of which I can’t even name.
I then decided to run away and live on the streets with my friends where I believed I'd be free.
There I got involved in gangs. I was the youngest among them.
We stole to get by and bought drugs and alcohol with whatever we managed to get on the day.
At first, it was small offences like break-ins and theft, then we moved to armed robbery.
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In 2004 we tried to rob a Shoprite store in Durban when we got into a shootout with police that left two people dead.
We were arrested and charged with armed robbery and murder.
We were found guilty by the Durban High Court and sentenced to life in prison (25 years).
I was 18 years old when I started serving my sentence at Westville Prison.
Life in jail was terrible. You woke up in the morning and stepped over blood or a corpse.
I never felt safe.
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My darkest time came in 2006 when I was sexually assaulted.
I went into a deep depression after learning I'd contracted HIV as a result of being raped.
I felt my life was over and made the decision to end it all.
I tried to hang myself but I was rescued by the guards who found me and took me to the prison's clinic for treatment.
I tried again later, this time consuming all the medication that was available and hoping it would do the trick.
Once more, I woke up in hospital.
As crazy as it sounds, I gave up after that.
I gave up trying to kill myself and started focusing on making peace with my situation.
I found solace in writing and reading and came to the conclusion that God had spared me for a purpose.
I became determined to help others.
In prison I was advised to appeal my sentence on the grounds of good behaviour.
The process took two years but it was worth the wait because my sentence was reduced to 10 years.
In 2012, after serving seven years, I received a presidential pardon and was released.
I reconciled with my family and started educating young people about substance abuse.
I also taught them that there is life after HIV.
After starting out in Empangeni in KZN, we moved to Mpumalanga before rolling out to the rest of the country.
In the past nine years, I've travelled to more than 100 schools nationwide to share my story.
I couldn't have done this work without the support of the department of social development and the South African National Council on Alcoholism and Drug Dependence.
I've also appeared on radio and television and managed to publish a book, Life behind Bars, which is available at Amazon.com.
The book is a personal account of my experiences in prison, the gang violence I encountered and was involved in, and all the lessons I learnt along the way.
I make no excuses for my wrongdoings, nor do I feel I've been dealt a bad hand.
I now understand the value of educating young people about drugs early on, and not just by teachers.
It's important for them to hear from people who've been there and done that.
That’s why I've dedicated the rest of my life to educating young people about drugs and peer pressure.
I hope my story serves as a cautionary tale about the dangers of drugs and crime.
But I also hope it lets people know they can change their lives and be part of the solution, no matter how hopeless things might seem.