Which of the following could be considered a suspicious package?

A backpack left unattended in a public area can be considered a suspicious package due to the potential risks it poses to safety and security. Unattended bags, backpacks, or packages in crowded or public places can be indicators of possible threats such as explosives or other harmful materials. This is especially true in environments where security concerns are heightened, as they may be used to conceal items that could endanger public safety.

On the other hand, a tightly sealed envelope with a return address typically does not present immediate cause for concern. The presence of a return address suggests there is potentially identifiable information about the sender, which mitigates the suspicion. Similarly, a package sent with overnight delivery may simply indicate a time-sensitive shipment rather than anything suspicious. Lastly, a box placed on a table in an office usually implies it is part of routine business operations and lacks the ambiguity that unattended items possess.

Understanding the nuances of what constitutes a suspicious package is crucial for effective security personnel in assessing risks and ensuring public safety.