So I was right about the boyfriend arrested
But if somebody put dead Petra in the park, it wasnt him - he was in a police cell.
Maybe their relationship was turbulent, and when they argued she used to leave and stay with a friend?
So he wasnt worried about her disappearance?
Maybe it wasn't the first time she'd left, so he thought nothing of it.
But for Petra, perhaps it was the last straw, and she was unhappy, distraught and suicidal. She may have felt trapped in many ways, work as well as love. So many reasons.
MOO.