回複：通常FBI指紋核對沒有這麼慢﹐可否告知是移民局什麼部門講

I call the 800 to request the status of my I485, I got a letter 2 weeks after.

Following are the contents:

The status of this service request is:

The processing of your case has been delayed. A check of our records establishes that your case is not yet ready for decision, as the required investigation into your background remains open.

Until the background investigation is completed, we cannot move forward on your case. These background checks are required to be completed on all applicants who apply for the immigration benefit your are seeking. We will make every effort to make a decision on this case as soon as the background checks are complete. If you do not receive a decision or other notice of action from us within 6 months of this letter, please contact us by calling our customer service number provided below.


What does this mean?