MongoDB/Mongoose returning empty array

I'm currently working on a project with mongodb/mongoose, and every time I purposely query for something that does not exist in the DB, I am getting a response with an empty array. This is my code for using Express to set up an API and return the data found in the DB:

app.get('/api/:id', function(req, res) {
var id = req.params.id;
Job.find({jobID: id}, function (err, foundJob) {
    if (err) {
        console.log(err);
    }
    else {
        res.json(foundJob);
    }
  });
});

However, every time I go to localhost:3000/api/67 (I have no object with jobID: 67 in the database yet), the console does not print the error. It gives me a JSON response with an empty array. Any ideas to why this is happening? The weird part is that when I change jobID: id to _id: id, it does give me an error. Why doesn't it do that for the jobID field?

via calviners