The youth has been identified as Manish Mishra (24) and he was arrested from Indranagar locality, IG (Rewa range) Gajiram Meeda said.
Manish is the brother-in-law of dismissed Madhya Pradesh Assembly Additional Secretary Satyanarayan Chaturvedi, he said.
Manish told police he wanted to talk to Bharti since the time of Uttar Pradesh Assembly elections but as he failed to get through, he "got angry" with her and threatened to kill her.