ABC News February 16, 2015

'Slender Man' Stabbing Suspect Expressed Fear Character Would Kill Her Family

WATCH: 'Slender Man' Stabbing Victim Recalls the Traumatic Event

One of the young girls who is accused of stabbing her friend in an effort to please a fictional character called "Slender Man" told a police officer she was convinced the character would kill her family, according to a police interrogation video.

The video of a police interview last year with Anissa Weier, one of the two defendants, was shown in a Wisconsin court today.

Girl Accused in 'Slender Man' Stabbing Says She Talks to Unicorns and Voldemort 911 Call Reveals Victim's Struggle in 'Slender Man' Stabbing

Weier, 13, and her friend Morgan Geyser were arrested after allegedly stabbing their friend 19 times and leaving her in the woods.

In the video, the then-12-year-old told a police officer she believed she had to kill or else the “Slender Man” would "kill my whole family in three seconds."

The footage was played in the Waukesha court today at a hearing on whether the two defendants should stand trial on adult charges, even though they were juveniles at the time of the crime, March 31, 2014.

Detectives also relayed some graphic testimony about the victim's condition, also 12 at the time of the alleged attack, and the stabbing episode.

Both Weier and Geyser have been charged with one count of first-degree intentional attempted homicide but Weier's defense attorney, Anthony Cotton, argued in court she should instead face a second-degree attempted homicide charge in juvenile court, according to The Associated Press. In Wisconsin, juveniles who are charged with the most heinous crimes are automatically sent to adult court. It is then up to the defendant to obtain a “reverse waiver” ruling from a judge that could sent the case to juvenile court.

Weier and Geyser have not entered pleas.