Small Transport; Low Wing; 2 Recip Eng
Distraction
Deviation / Discrepancy - Procedural Security; Flight Deck / Cabin / Aircraft Event Passenger Misconduct
General None Reported / Taken
Human Factors
While boarding; a young woman sat in the co pilot seat.  We talked while the other passengers were boarding. She asked me if I had ever had problems with someone being; 'naughty' in the co pilot seat.  I asked her to clarify her question.  She asked if anyone touched the controls.  I explained that post 9/11; there is zero tolerance for anyone touching the controls and if someone did; I would have to report them to the police.During the taxi out she took out her phone and started to take a picture of herself with her hand on the yoke.  I said; 'No!' loudly and moved her hand.  I told her do not touch the controls.She sat quietly for the next 30 minutes or so but then as we were crossing the shoreline [nearing our destination]; she again grabbed the yoke with her left hand and tried to take a picture with her phone in her right hand.  I swatted her hand away again.  As we approached [destination]; I called in range to the gate and asked that a Law Enforcement Officer (LEO) meet my plane because a passenger has grabbed the controls twice.  The ops agent assured me that he had called.I pulled up the the gate and saw several people standing by the double doors.  I assumed one or more were police officers.The passengers disembarked and I followed behind; scanning for the LEO.  There was no one.  I went through the gate doors and looked there.  Then I went to baggage claim and looked there.  There were no police officers.  After that; I rushed to our ticket counter to see if they were waiting there.  Again; there was no one.  I asked an employee for the manager and she said he was in his office.  I found him there and asked where the police were.  He was not aware of the situation.  Two officers showed up about 5 min after I arrived at the manager's office.  They said they got the call but had gone to the wrong airplane.I should have waited to pull into parking until I was sure the LEO was there.
A twin engine piston pilot reported a passenger grabbed the controls multiple times after being told to stop and asked for Police to meet the flight.  However; upon landing the Police went to the wrong gate.