Final answer:
An indicator of a terrorist act involving explosives includes the intentional use of violence or threats to instill fear for political, religious, or ideological reasons, often targeting civilians indiscriminately. The presence of unusual items, materials, or situations like those identified by soldiers using metal detectors can signify the potential for such acts. Increasing security measures and intelligence reports are also indicators.
Step-by-step explanation:
An indicator of a criminal terrorist act involving explosives is the intentional use of violence or the threat of violence to create fear and achieve a specific political, religious, or ideological objective. This could manifest in several ways, including the discovery of suspicious packages or devices, unnaturally placed containers like pressure cookers (as seen in the Boston Marathon bombing), or unusual chemical odors or residues that could suggest the presence of bomb-making materials. Soldiers, for example, might use metal detectors to locate hidden explosives which is a method employed in conflict zones to ensure safety.
Terrorism is intended to create fear among the public, receive attention for a cause, and often targets civilians indiscriminately. Indicators may also include the aftermath of an explosion, increased security measures, and intelligence reports suggesting potential threats. With a rise in both international and domestic terrorism, recognizing these signs has become crucial for prevention and response.