An Ohio teen and her boyfriend allegedly plotted to kill the girl's parents because they disapproved of the couple's age difference.

Grace Dillman and Robert Best, ages 16 and 20, are charged with attempted murder following a botched attack on Dillman's parents early Wednesday morning in Gahanna, the Columbus Dispatch reported.

Court records accuse Dillman of planning the killing a month in advance. She reportedly intended for Best to slit each of her parent's throats while they slept, according to CBS.

Alan Dillman, Grace's father, woke up when Best entered his bedroom. The father entered a struggle with his daughter's boyfriend, who allegedly stabbed him in the back as they fought.

Authorities say that Dillman and Best met online when the girl was 13 years old, according to 10TV.

Best is also charged with attempted aggravated murder and felonious assault.

Also on HuffPost: