Is this a safety or a security issue?
What exactly is the threat to the aircraft? What history do you have of incidents in situations such as you have outlined? What extra legislation are you now subject to?
There is no such thing as "security" or "safety". There are a range of measures that you put into effect and monitor on a positive feedback loop to guard against perceived threats.
As incidents and incident precursors occur, you alter the measures accordingly.
And you remember that there is no such thing as being 100% safe.