Under which circumstances are DNA samples collected according to acceptable police practices?

The correct answer is grounded in the legal standards and practices surrounding DNA sampling for law enforcement purposes. DNA samples are typically collected from individuals who are involved in serious criminal activity, particularly felonies that carry significant punishments. In this context, the collection is often permissible for felonies that result in sentences of five years or more, as well as certain minor offenses that are deemed relevant under specific legal frameworks or state laws.

This practice aligns with the objective of using DNA evidence for investigative purposes to both solve and prevent crime, while also considering the implications of individual rights and privacy. The selection of felonies with longer sentences reflects an emphasis on serious criminal behavior, ensuring that samples are collected from those considered a higher risk.

The other options do not accurately represent the guidelines under which DNA sampling can be conducted. Collecting samples for any arrest, irrespective of the crime, could lead to a violation of individual rights, given that not all arrests warrant such an invasive procedure. Similarly, limiting the collection of DNA samples to only violent felonies does not account for the broader spectrum of serious crimes that may also warrant sampling. The idea that samples should only be collected in schools and public events ignores the need for comprehensive practices applicable across various settings where serious crimes might occur.