Navi Mumbai: Mangaon police on Wednesday arrested a 34-year-old man in a murder case within 24 hours after the body of a 15-year-old girl from Mumbai was found in the hilly forest area in Raigad district. She was strangled to death, said police, who are yet to confirm the murder motive.Preliminary post-mortem report has ruled out sexual assault, but police are awaiting the forensic report.Both the alleged accused, Shubham Utekar, and the deceased, Nidhi Utekar, resided in Vile Parle and hailed from Palasgaon village in Mangaon.Police said Nidhi, who had cleared her class IX exams, had arrived at her hometown with her parents and brother a few days ago. Shubham, who is married, too had come to his village recently.Police said Nidhi was last spotted on Monday evening talking to someone on her father’s phone. They suspect that she was speaking with Shubham, but are yet to verify it.On Wednesday, locals found a girl’s body in the forest area and alerted police. They contacted Nidhi’s father, who had filed a missing person’s complaint, and he identified her body.Police inspector Sanjay Bangar formed four police teams to trace the accused and zeroed in on Shubham.The post-mortem examination conducted at the sub-district hospital in Mangaon confirmed death by strangulation referring to the marks on the neck, besides four deep injuries on the head indicating the use of sharp weapons to commit the crime, said sources.