The crime took place at the home belonging to the family of Tran Manh Hung, a 22-year-old local man.
Ha Nam police arrested Hung five hours later on Wednesday evening.
At the police station, Hung said that he and V. had been in a relationship.
The man took the teenager to his parents’ house for an overnight stay on Tuesday.
Around mid-Wednesday, knowing that V.’s family was looking for her, Hung strangled the teenager.
He then jumped into the pond next to his house to commit suicide but failed.
After that, the suspect went to the Thai Ha Bridge in the same district to attempt another suicide, but he was arrested by police officers.
Police are continuing their investigation to find out his motive.