A Florida teen is on trial for allegedly murdering his mother, 18 months after he killed his father, claiming he acted in self-defense in both incidents.

Collin Griffin, 17,  faces charges of kidnapping and first-degree murder in the stabbing death of his mother, Catherine Griffith, on September 8, 2024. He told 911 dispatchers that she “fell on a knife” during a “very long fight.”

As CrimeOnline previously reported, police said the defendant killed his 39-year-old mother in her home in Auburndale. Colin then called 911 and when investigators arrived, said that during an argument with his mother, she lunged at him with a knife and fell on it, causing a deep stab wound to her neck.

Shortly before the killing,  he fled to his grandmother’s house in central Florida. Prosecutors alleged that Catherine went to retrieve her son on September 8, 2024. and within 30 minutes of her arrival, witnesses reported seeing Collin dragging her by her hair.

On Tuesday, his grandmother, Susan Detman, testified that her daughter, had been Baker Acted several times and had a tumultuous relationship with family members. She told jurors that her daughter was unpredictable, Tampa Bay 20 News reports.

The incident happened after a November 2023 altercation, when police arrested Collin on a domestic violence charges. After an altercation with his mother. Colin reportedly told police that he didn’t want to return to her custody.

”I’m in a constant state of fight or flight,” he told deputies, according to Court TV. “If I think she’s going to do something, even if she’s not, I might act. I’m not going to, like, go crazy or anything, but I’m not sure, honestly.”

Collin alleged his mother threatened to kill him, herself, and asked him to use the gun on her. Catherine denied the claims, according to court documents, telling deputies Collin was upset because she took away his phone and AirPods over his failing grades.

She added that Collin has severe PTSD from being held captive by his father, Charles Griffith, for 1,041 days in Oklahoma without contact with others.

Months earlier, the teen killed his father.

A 2023 affidavit from by Lincoln County News in Lincoln County, Oklahoma, indicated that Collin, 15 at the time, shot and killed his father, Charles Robert Griffith, during a Valentine’s Day altercation.

Collin reported that an argument occurred between him and Charles, during which Charles allegedly pulled a knife and chased him through the house. Collin claimed that Charles trapped him in the bedroom, leading him to grab a gun and shoot Charles twice—once in the head and once in the chest.

Meanwhile, a medical examiner who examined Cathy’s body the day after her murder testified Friday that the injuries did not appear accidental. He reviewed photos showing deep wounds and bruises across her body.

He explained that the wound causing her death was inflicted by another person. When the state asked if the injuries could be accidental, he asserted that it would be “rather extraordinary” if they were.

Cathy Griffith’s father, Robert Walantas, who also testified Friday, said that his grandson told him he wanted to kill his mother.

“He said, ‘I keep thinking over and over I wanna slit her throat. I want her to bleed out. I wanna feel the life and blood leaving her body,” Walantas testified.

Closing arguments are currently underway. Check back for updates.

[Feature Photo: Collin and Catherine Griffin.Instagram;Collin Griffith/Polk County Sheriff’s Office]