Tiffany Johnson celebrates two birthdays: one on the day she was born, and another on April 28 — the day she was released from prison after 16 years.

For her fifth birthday, her mother Caroline went shopping and returned with an armload of presents, along with the man who paid for them.

That memory is vivid, but much of my early childhood is a blur. It included constant movement and a brief stint in foster care until my mother was able to reclaim us four kids.

The birthday man — they called him Ernie — was wealthy, older, white and married. He was a professional tennis coach who owned a couple of shops in Oakland and trained celebrities.

And he was a predator.

Soon after Caroline brought Ernie home, he began fondling Tiffany. The fondling gradually led to oral sex, and eventually full-on intercourse. He took her, and her alone, shopping for groceries or clothes. Every trip involved stopping first for sex: sometimes in the car, other times at his house.

At his tennis shops, he would stash Tiffany underneath the sales counter and force her to perform oral sex on him while he was tending to the customers.

He told me I was his “special little girl” because my mother brought him home on my birthday. He was my gift, a keepsake to treasure. Our secret.

It went on for five years; half of her life.

Shortly after she turned 10, her menstrual cycle made its first appearance. That’s when the sex abruptly stopped. Her rapist wanted to eliminate any evidence of his crime, avoid explaining the birth of a biracial child.

For the next decade, even though he was still part of her family, Tiffany blocked out the Ernie nightmare. She drifted into addiction. Sex became a kind of drug, too.

Most people who are abused either never want to have sex again or they’re constantly seeking attention, confusing the act with intimacy. I went from relationship to relationship. I had the oldest of my four children, Tivon’ta, at 16; four years later the twins, Tyree and Tyshea, and three years later came Troy.

The memories bubbled up when Tiffany began to suspect that Ernie had molested her niece. Trapped, desperate to escape the memory, she tried to shove the horror back under the floorboards.

It was Memorial Day. I was at my mother’s house. Ernie was there, still a standard fixture — only now, Mama knew what he had done. A crude comment Ernie aimed at my younger sister sparked a violent fight with Mama, who ultimately stormed out of the house.

Ernie turned to me. “Why did you tell?” he shouted. He had treated me well, hadn’t he? “I never hurt you.”

“I never hurt you.” His words cut through me like a buzz saw to my brain.

Never hurt me? You stole everything from me! My flesh, my innocence, my future. You left me damaged. Any hope of a happy, well-adjusted life was gone before I’d lost my first baby tooth.

And now, it seemed, he had turned his attention to her niece. Would her little Tyshea be next?

Tiffany doesn’t remember what happened next. One moment she was motionless, panic-stricken; the next moment, her mother was standing over her, slapping her into consciousness.

“What did you do?” Mama screamed. “WHAT DID YOU DO?”

She had killed him. Wielding a kitchen knife, she stabbed him over and over but couldn’t remember how many times.

I was dazed; didn’t know what to do or say. Mama hustled us all into the car and drove into the night. We dropped my kids off with my brother in Sacramento and headed south. We could escape to Texas.

But then Tiffany thought about her children. Her babies. If she ran, she would never be able to see them again.

I thought, I can’t do this. I can’t go into hiding and never see my kids again. When we reached Los Angeles, I told Mama to turn the car around. Running wasn’t the solution. We went back and I turned myself in.

Unable to afford an attorney, Tiffany placed her trust in a public defender. He pushed her into a plea bargain, telling her that she would serve less than seven years. She did 16.

Her children, aged 9, 5 and 1 when she went to prison, were all adults when she was released at the age of 41.

It was April 28, 2010. Tiffany, herself barely an adult when she surrendered to the police, had to learn to navigate the world outside.

It would take time to acclimate to this strange new liberty. There would be speedbumps, both surprisingly small and dauntingly large. But building on the inner healing she did during those 16 years of confinement, Tiffany found solid ground.

The day-to-day, what you are already prepared for, is easier to deal with, even if it’s mostly hardship. But taking the first step — the unfamiliar, the unknown — opens up a world of possibilities.

Today, she is emerging as Susan Burton’s successor at A New Way of Life Re-Entry Project. The challenges, responsibilities and way forward seem immense.

Seven years after stepping beyond those prison walls, the bond with my children, tested by so many years apart, is strong. I feel blessed to undertake my work with women coming home because I see parts of me in all of them. And when April 28 rolls around each year, I celebrate. It’s my new, untarnished birthday.

Tiffany Johnson, 48, is associate director of A New Way of Life Re-Entry Project. The mother of four served 16 years in state prison on second degree murder charges after killing her abuser who began violating her from the age of five.