httpss://www.youtube.com/watch?v=ySy8mcceTno

A teenager involved in an attempted murder to honour an online horror character has been sentenced to 40 years in a mental hospital.

Morgan Geyser, along with Anissa Weier, lured the victim into the woods and stabbed her 19 times.

Investigators said Geyser stabbed the victim, while Weier urged her on.

The girls said they committed their crime in dedication to Slender Man, a fictional horror character, who told them to do it.

The judge gave Geyser the full sentence prosecutors sought, arguing she remains a risk to herself and others.

Geyser, now 15, broke down in court on Thursday while apologising to the victim and her family.