When entering the US by car via a Sentri lane as a US lawful permanent resident (LPR), the CBP agent often takes over a minute on their computer to decide whether to allow the US LPR to enter the US, not counting the questions that they may ask, verifying that the US LPR looks at the same as on their Permanent Resident Card nor the quick visual inspection of the vehicle. This makes me wonder: What are CBP agents doing when deciding whether to allow a US LPR to enter the US?