Why was it that he didn't just call the cops?

[Auntie]

In the 5th season I believe , with Richard Thomas, in the beginning scene where they showed him at the airport 'going away', why was it that he just kept running away from the woman who was appearently threating him(with the letters)? Why not have just had a restraining order against her?

[Godlovesyou]

Mabye he was afraid she would send someone else after him to do the dirty work for her if she couldn't do it herself.