Man details traumatizing moment he testified at 7 years old that he saw his mom drown his sister

Warning: This article contains discussion of child abuse which some readers may find distressing.

A man has spoken out about the traumatizing moment he had to testify against his biological mom as a child after witnessing her murder his sister.

AJ Hutto was just seven years old when he told a Florida courtroom his mom, Amanda Lewis, killed his sister in the family swimming pool.

AJ, whose name has been changed and is protected, rocked the court and entire nation back in 2008, when he recalled the harrowing moment his mom 'dunked' seven-year-old Adrianna's head underwater and drowned her.

His testimony of the crime went on to prove instrumental in the case, with Lewis convicted by a jury of first-degree murder and handed a life sentence behind bars without parole, though she continues to protest her innocence.

Now, 24-year-old AJ has spoken out for the first time in 17 years since the dramatic case concluded, telling DailyMail: "One hundred per cent guilty. I stand by every word I said."

The young man, who was adopted after the trial, has since gotten married and become a firefighter in his adult life. He's had no contact with 45-year-old Lewis, and wants to keep it that way, reports the news outlet.

Amanda Lewis has protested her innocence ever since the trial in 2008 (ABC News)

As a result, he is protecting his new identity and also refuses to refer to Lewis as his mom.

Back in the trial, AJ's stick drawing of the three around the pool was brought forward by prosecutor Larry Basford, who argued the picture shows how the young boy witnessed the distressing scene.

The then-seven-year-old said his 'momma' was in the picture 'killing my sister'.

When asked how Lewis was murdering her, he replied: "Putting her hand over her face."

He also scribbled the words 'She Did' on the drawing, which he told the court meant 'she died,' while 'To Bad' written on the picture meant 'it was scary'.

At the time, Judge Allen Register ruled the boy was a competent witness, despite his age, though campaigners argued he was led by the prosecution team and highlighted some of his inconsistent answers.

AJ told police that his mom 'dunked' his sister in the water (ABC News)

Addressing this, AJ told the news outlet: "I don't believe I was, what they've called, coached or anything like that. I just told them exactly what I saw word for word."

Adriana died in hospital after the incident, but Lewis has a very different version of events.

The mom claimed that the girl had fallen in the pool and was 'purple' when she found her face down in the water before calling 911.

The authorities initially believed it was a tragic accident, until AJ's testimony and an autopsy report noted a bruise resembling a handprint on Adriana's face.

The young boy told police in a videotaped interview: "Mama dunked my sister," and revealed his mom had become angry with the girl for spraying glass cleaner in the home.

Investigators also found the family home was squalid and didn't have many toys for the children.

AJ also spoke about his childhood with Lewis, saying there was 'just darkness', 'trauma', and 'a lot of abuse'.

"Physically abused, both Adrianna and I were hit," he continued, as he went on to describe the difference between his childhood home and that of his adoptive family as 'night and day.'

The young girl had drowned in the pool (ABC News)

"My childhood with Amanda was, it was almost a 360 difference, completely different.

"It's been a long time since I've had to talk about it, so I kind of remember some things about my previous life. And for the most part, I remember the abuse. Sometimes we wouldn't even see it coming. It was literally sometimes we were blindsided."

According to the outlet, Lewis has recently appointed an attorney in a bid to reopen her case from Homestead Correctional Institution for Women, south of Miami, where she is serving life without parole plus 30 years for child abuse.

She passed a lie detector test and has refused a plea deal of 10 years for manslaughter.

If you’ve been affected by any of these issues or want to speak to someone in confidence regarding the welfare of a child, the Childhelp USA National Child Abuse Hotline (1-800-4-A-CHILD (1-800-422-4453) operates 24 hours a day, seven days a week, and receives calls from throughout the United States, Canada, US Virgin Islands, Guam and Puerto Rico.