The sister of Charleston church shooter Dylann Roof was arrested Wednesday after bringing a knife to school with her and threatening students participating in the walkout against gun control. Morgan Roof is pictured in her mug shot

The sister of Charleston church shooter Dylann Roof was arrested Wednesday after bringing a knife to school with her and threatening students participating in the walkout against gun control.

Morgan Roof has been charged with simple possession of marijuana and two counts of carrying weapons on school grounds, WISTV reported. She has been released on a $5,000 bond, but was not allowed to return to the location of the incident - AC Flora High School.

The 18-year-old was apprehended after the student body was alarmed due to a threatening post on her Snapchat, in which she said she hopes students participating in the National Walkout Day 'get shot.'

'We know it's fixing to be nothing but black people walkin' out anyway,' she added.

The post was particularly alarming given her brother, Dylann Roof, opened fire on a church in Charleston, South Carolina, brutally murdering nine black parishioners on June 17, 2015 in an effort to start a race war.

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The sister of the Charleston church shooter Dylann Roof was arrested Wednesday after bringing a knife to school with her and threatening students participating in the walkout against gun control

Morgan Roof has been charged with simple possession of marijuana and two counts of carrying weapons on school grounds, WISTV reported. She has been released on a $5,000 bond, but was not allowed to go back to school

The 18-year-old was apprehended after the student body was alarmed due to a threatening post on her Snapchat , in which she said she hopes students participating in the National Walkout Day 'get shot'

Thousands of students across the United States walked out of their school on Wednesday, on the month-anniversary of the Parkland school shooting, to protest gun violence.

The school she attends, AC Flora, was one of the schools that participated.

In her Snapchat post she made clear she disagrees with the walkout and went on to say: 'we know it's fixing to be nothing but black people walkin' out anyway.'

'Your (sic) walking out for the allowed time of 17 min, they are letting you do this, nothing is gonna change what tf you think it's gonna do?' she wrote in the post.

'I hope it's a trap and y'all get shot we know it's fixing to be nothing but black people walkin out anyway. No offense ofc buuut (sic).'

In her Snapchat post she made clear she disagrees with the walkout and went on to say: 'we know it's fixing to be nothing but black people walkin' out anyway.' She is pictured left with her father Frankln Roof just after her brother committed the massacre in 2015, and right in a Snapchat photo

Her brother Dylann Roof is a self-avowed white supremacist. He is pictured in June 19 in an image from a video uplink from the detention center to the courtroom during his charging

He pleaded guilty to nine counts of murder and three counts of attempted murder in the 2015 massacre at Charleston's historic Mother Emanuel AME Church

On her person when she was arrested was a knife, marijuana and pepper spray.

No students were harmed as a result of this incident.

Morgan has been taken to to the Alvin S Glenn Detention Center, and Richland County Sheriff Leon Lott said the school's administration acted appropriately by alerting the department of the potential threat.

The school issued a statement to parents on Wednesday to explain the situation and say that the comment was 'not a threat, but was extremely inappropriate.'

'A student used social media to post a hateful message,' the letter to parents read.

'The posting was not a threat, but was extremely inappropriate. That student was dealt with in a swift and severe manner as the posting caused quite a disruption.'

South Carolina Governor Henry McMaster also issued a statement saying: 'potential tragedy was avoided at AC Flora High School.'

'In two separate incidents, students and educators reacted quickly to reports of suspicious activity and behavior to their Richland County Sheriff's Department school resource officer. We owe a debt of gratitude to all involved who acted so quickly and decisively.'

Throughout his trial a disturbing picture was painted of the Roof family. Growing up the children were allegedly victim to and witness of domestic abuse

During the trial videos of Morgan's visits to Dylann in jail were released, which show that he caused his sister and parents distress while behind bars. Roof is pictured as he enters the church just before killing the nine parishioners

In one video she is featured telling him he loves her as he refuses to say it back to her. Morgan and her father are pictured just days after Roof shot up the church in 2015

Morgan's brother Dylann Roof is a self-avowed white supremacist. He pleaded guilty to nine counts of murder and three counts of attempted murder in the 2015 massacre at Charleston's historic Mother Emanuel AME Church.

The 21-year-old is currently on death row in Indiana.

Throughout his trial a disturbing picture was painted of the Roof family.

Growing up the children were allegedly victim to and witness of domestic abuse.

However, the siblings were said to be raised by a loving stepmother, Paige Mann, who married their father Franklin Roof.

During the trial videos of Morgan's visits to Dylann in jail were released, which show that he caused his sister and parents distress while behind bars.

In one video she is featured telling him he loves her as he refuses to say it back to her.

'Roof's teenage sister, Morgan, told him that she wanted to attend his execution, if it occurred,' The Post and Courier reported.

'I love you, Dylann, even if you don't love me back,' the paper said she tearfully told him.

He apparently responded: 'Ok.'