My brother, Tom, and I were never close. He was two years older than me. I don’t know why, but my parents sheltered him. They were farmers and we lived in Kansas with three older half-siblings. All us kids were in competition for their attention.

I moved out at 18 and found work at a local dairy farm where they were willing to teach me. My parents and Tom lived five miles away but I didn’t visit much. By the time I was 23, I was living with my wife and our two young sons. We’d been married three years but the relationship was rocky. That August, my wife’s sister, Camille, who was 14, moved in with us.

One Friday evening in November, I was at work when my mother-in-law called asking if I’d seen Camille. I told her I hadn’t and she could check our house. Camille wasn’t there. That night we made calls and drove around, but there was no sign of her. Night turned into day and our dread grew. We searched and passed out flyers.

On Monday morning, we were home when the police said they’d found her body. They told us they’d arrested a murder suspect and it was my brother. He’d turned himself in, saying he’d shot her. I felt like someone had taken a plank of wood and hit me in the chest.

We were in shock and mourning. A couple of days later, a detective asked me to do a polygraph test. I went willingly, but afterwards was told I’d failed the test and my brother had passed; I didn’t understand.

I was put in jail. I wasn’t allowed to call anyone and it was my first night away from my sons. For three days I was left in a cell. I was numb, walking around in confusion. I tried sleeping but it was so cold. I was given food but no one talked to me. I felt crazy.

They moved me into a communal cell and gave me an attorney who kept saying he’d be in touch. I saw on the news that my brother had been released. The whole thing was the final straw for my marriage and my wife filed for divorce.

My parents visited but avoided the reason I was there. I told my mum: “Mum, I didn’t do it,” and she said, “Well, I know Tom didn’t do it.” She added that I’d be blaming my dad next.

Six months later I was put on trial. My brother had withdrawn his confession and my parents testified that, at the time of the murder, he was home with them, sleeping. I can’t describe how much that hurt. They didn’t look at me. Not all my alibi witnesses were called. When the jury found me guilty, I bawled my head off. I was sentenced to life. I was so angry towards the prosecutor, the detectives, Tom, my parents.

I had bouts of depression in prison. Christmas and birthdays were hardest. But I met a lot of good people who believed me. I went through appeals and was referred to Kansas University School of Law.

It was late 2014 when we did DNA testing. Tom’s DNA was found on Camille’s body. We gave it to the county court who stalled, saying it had to conduct its own investigation. My attorneys sent out a press release about the results. A week later my brother killed himself, leaving a note in which he admitted to the murder and said I was innocent. The original polygraph exams were later found to be invalid.

After 15 years in prison, on 8 December 2015, in shackles, handcuffs and a belly chain, a judge told me I was free. It felt like bliss. I walked out at 3.30pm and went to a restaurant to celebrate with my attorneys and interns. I couldn’t thank them enough.

I’ve seen my parents once. My mum had been hospitalised and when I walked in and saw this old lady, struggling to breathe, all I had was compassion. My father was standoffish, but I learned in prison that I had to forgive them and all the people who wronged me. I can’t let their actions control me. It’s a decision I make daily.

I’m active in prosecution reform, and married a volunteer from prison. My first two kids grew up not knowing about me until they were older. They call another man Dad; I’m just Floyd to them.

But my wife and I had a daughter a year ago. We gave her the middle names Alice and Jean, after two of the attorneys who gave me back my life.

• As told to Candice Pires.

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