new
    Float: pX,
    Float: pY,
    Float: pZ;

GetPlayerPos(id, pX, pY, pZ); // edit "id" to the variable you store the player's ID who is about to be arrested
if (!IsPlayerInRangeOfPoint(playerid, 10.0, pX, pY, pZ)) return // error message (not close enough)

new pos[3];
GetPlayerPos(playerid, pos[0], pos[1], pos[2]);
if(IsPlayerInRangeOfPoint(idOfUserToGetArrested, 10.0, pos[0], pos[1], pos[2])) {
    // In range!
} else {
    // Not in range!
}