"Just two, officer" is the most common response, with uses the unnecessary word, "just", indicating that the subject is thinking of "two" from a reference point of "greater than" two.
In my own work, I have found Mark's conclusion to be accurate. Psychologically, my research has shown (though interviews) that "2 sounds too little, but 4 sounds too much" seems to be the basis for the choice.
In looking at "Fake Hate" allegations (something very popular in our day), the number 3 shows up frequently. The timing, however, is something that we, in researching, should be mindful of.
Recently, a family from Long Island claimed an anonymous threatening letter telling them to move out because they are black. Analysis shows that this is a deceptive letter, and does not threaten, nor show racial animosity towards black people. It comes on the heels of the Baltimore riots.
In Texas, 2014, a Bosnian resident was killed. This is the timing fro Seherzada Dzanic's claim.
She said that "3 black men in their late teens or early 20's" had pulled a gun on her, about 5:25am on December 5, 2014, and rifled through her purse.