Amends the Missing Persons Identification Act. Requires a law enforcement agency to attempt to obtain a biological sample from closely related family members of the missing person or a personal item of the missing person beginning 30 days after the date of the missing person report (rather than within 30 days after receipt of a report). Provides that a law enforcement agency may not establish or maintain a policy that requires the observance of a waiting period before accepting a missing person report. Modifies the circumstances under which a law enforcement agency may not refuse to accept a missing person report. Requires a law enforcement agency to notify a person responsible for the missing person's welfare, or other specified individuals, about specified efforts to locate a missing person. Provides that, if a person remains missing for 30 days after the date of report, the law enforcement agency shall immediately (rather than may) generate a report of the missing person within NamUs, and the law enforcement agency shall (rather than may) attempt to obtain specified information and materials that have not been received. Modifies the follow-up action required by a law enforcement agency after creation of a missing person report. Modifies the definition of "high-risk missing person". Upon receipt of a missing person report (rather than immediately), requires the responding local law enforcement agency to enter all collected information relating to the missing person case in the Law Enforcement Agencies Data System and the National Crime Information Center. Makes other changes to reporting requirements. Modifies requirements for submission of fingerprints from unidentified remains for analysis as well as other requirements relating identified human remains. Provides that an assisting law enforcement agency, a medical examiner, a coroner, or the Illinois State Police may not close an unidentified person case until the individual has been identified and must keep the case active. Requires the coroner, medical examiner, or assisting law enforcement agency (rather than the coroner or medical examiner) to obtain a biological (rather than DNA) sample from an individual whose remains are not identifiable, and modifies how the sample may be analyzed and labeled. Makes other changes.