Why do professional arsonists use delayed ignition devices?

Professional arsonists utilize delayed ignition devices primarily to give themselves time to escape the scene. This tactic allows them to ignite a fire while distancing themselves from the immediate area, minimizing the risk of being caught during or immediately after the act. By using a device that creates a delay before the fire starts, the arsonist can leave the vicinity and blend in with the crowd or return to a more normal state of activity, thereby reducing suspicion.

The other options do not align with the primary motivations of arsonists. Creating more impressive fire displays may be a secondary consideration, but it does not serve the main purpose related to their escape. Increasing the value of an insurance claim could be a factor in some arson cases, but it is not directly connected to the use of delayed ignition devices. Similarly, while preventing immediate investigation may indirectly result from the delay, the primary intent behind using such devices is to ensure a safe getaway for the perpetrator.