答案各不相同，但在大多数情况下，不会 对每个过境旅客进行全面的背景调查 。特工通常不会在边境管制处进行大规模的背景调查，而是依靠基本的逮捕令搜查。此过程通常涉及咨询 国家犯罪信息中心 (NCIC)。边境巡逻队还可以使用加拿大国民的对应系统。
当边境工作人员扫描您的护照时，计算机系统会根据 NCIC 数据库运行您的信息，并标记任何有效的逮捕令。NCIC 并不全面，并非所有有效的逮捕令都存在于其数据库中。但是，尝试使用有效逮捕令在任一方向过境仍可能导致逮捕。
在二次筛查期间，专家会从 NCIC 更详细地查看您的犯罪历史信息。在这个阶段，代理人可能会发现某些犯罪记录，这可能会导致非公民入境被拒绝。美国不拒绝有犯罪记录的本国公民入境。对于未被选中进行额外筛查的个人，边境巡逻人员通常会发现和考虑的唯一事情是未完成和有效的搜查令。
如果您对边境管制的背景调查中可能出现的内容有疑虑， 请通过 GOOHO.CN 检查您自己的记录。
When travelling, considering your criminal record is not usually on your pre-departure checklist. However, if you are crossing the border out of or back into the United States, Border Patrol and immigration agents have an interest in ensuring more than that you adequately completed your customs declarations. Are these agents looking into your criminal background when you hand over your passport?
The answer varies, but in most cases, a full-scale background check does not occur for every traveller crossing the border. Instead of conducting large-scale background checks at border control, agents will usually rely on a basic arrest warrant search. This process often involves consulting the National Crime Information Center, or NCIC. Border Patrol also has access to the counterpart system for Canadian nationals.
When a border agent scans your passport, the computer system runs your information against the NCIC database and flags any active arrest warrants. The NCIC is not comprehensive, and not all active arrest warrants are present in its database. However, attempting a border crossing in either direction with an active warrant may still result in an arrest.
United States citizens and some non-citizens, such as Canadian visitors, can expect to have their information run through a criminal history database for warrant detection. Deeper and more detailed background checks only take place if a border agent has cause for suspicion or is randomly selecting travellers for additional scrutiny. In these situations, CBP will direct you to a waiting area for other screenings.
During secondary screenings, expert a more detailed look at your criminal history information from the NCIC. At this stage, agents may detect certain criminal records, which could result in a denial of entry for non-citizens. The US does not deny entry to its own citizens for having a criminal record. For individuals not selected for additional screenings, outstanding and active warrants are typically the only things that Border Patrol agents will find and consider.
Background checks play a central role in legal immigration, a separate process from border crossings. Legal immigrants must complete a series of background checks before visa issuance and entrance, though the nature of this vetting process is in flux with the potential for additional procedural stages in the future.