Police have been able to thwart a terrifying plot by a deranged St. Louis teenager to kidnap his friend 's 10-year-old sister in the middle of the night , then allegedly smother her to death and rape her dead body , authorities say . John Thomas Classen , 17 , is now in custody after breaking into his classmate 's home in O'Fallon around 12.40am Thursday , using a window he deliberately left unlocked two days earlier , and hiding in the basement for over four hours . He then went up to the main level of the house , where the young girl - who he was reportedly in love with - was asleep on the couch , put his hand over her mouth and threatened to kill her if she screamed . Classen then allegedly dragged her to the basement , but the two slipped and fell down the stairs . Scroll down for video . Deranged : John Thomas Classen , 17 , of O'Fallon , Missouri , was 'in love ' with his friend ’ s 10-year-old sister and kidnapped the girl early Thursday , planning to smother and 'rape her dead body ' , then flee town , police said . Classen allegedly took his victim out the window he used to get into the house - located in the 100 block of McCluer Drive - and then to his car , which was parked in a nearby street . The girl continued resisting . He drove off , headed for a wooded area next to an apartment complex . 'He wanted to talk to her about the first time they met , ' the victim 's 18-year-old brother , who asked not to be named , told The St. Louis Post-Dispatch . 'My sister told him she was hurt and wanted to go back home . ' Meanwhile , back at the house , the family 's three dogs started barking at the sound of Classen and the victim tumbling down the stairs . The mother woke up , now about 5.25am , and started screaming after realizing her daughter was missing . She looked outside and allegedly saw Classen dragging her little girl down the street and quickly called 911 . Scene : Classen allegedly broke into this O'Fallon home around 12.40am Thursday , using a window he left open while visiting the house two days earlier . He hid in the basement for four hours before kidnapping the victim . Police established road road blocks using a one-mile radius and we able to stop Classen at a checkpoint near the entrance to the Prairie Village subdivision , off the South Outer Road of Highway 364 . The girl was rescued , shaken and with minor injuries . Police found a list on Classen 's cellphone that detailed his plans . 'Take her to a secondary location , explain everything to her , smother her , rape her dead body , clean up and then pose the body … photograph her , dispose of her body , leave town , ' police documents stated . 'We were very , very fortunate to get on it right away , ' O'Fallon Police Chief Roy Joachimstaler said . The victim 's brother goes to school with Classen at Fort Zumwalt West High School . They have known each other for about five years . The brother said he first realized something was amiss last summer , when Classen sent his sister a message on social media . It said he thought she was a cute and that he loved her . ' I took it in the best possible way and thought he was just being friendly , ' he brother said . Safe : The 10-year-old victim is seen here being attended to by ambulance officers following Classen 's arrest . Injured : The girl had a sore ankle from the fall down the stairs and scratches on her back , but was fine . Arrest : Quick-thinking police were able to intercept Classen within 35 minutes of him snatching the girl . The cellphone Classen wrote said that he was going to rehearse the abduction and wear latex gloves . After pulling off the alleged rape and murder , he planned to flee town and hide in a foreclosed home , and surviving by stealing cars and money . Part of the note read : 'She will die as she lived , my only friend . The darkness has engulfed everything … I ’ ll miss you . ' Classen has been charged with child kidnapping , burglary and two counts of child abuse . 'This is one of those things that makes no sense ; there ’ s no logical reason behind it , ' the brother told STLtoday . ' I hope he gets punished and that he gets some mental help . ' Classen 's bail was set at $ 1.5 million .
John Thomas Classen , 17 , broke into friend 's home at 12.40am Thursday . He used a window he left unlocked two days earlier . Hid in basement for four hours before snatching sister , 10 , who he 'loves ' Victim 's mom woke up and called police . Cops were able to stop Classen at a checkpoint and rescue the girl . Police say he planned to smother her and rape her dead body .