National Forensic Sciences Improvement Act of 1999

National Forensic Sciences Improvement Act of 1999 - Amends the Omnibus Crime Control and Safe Streets Act of 1968 (the Act) to: (1) include among permissible uses of drug control and system improvement (Byrne) grants improving the quality, timeliness, and credibility of forensic science services for criminal justice purposes; and (2) require State certification that it has established a forensic science laboratory or laboratory system or a medical examiner's office that meets specified requirements, with respect to any such grant for such purpose.

Amends the Act to require a State to submit to the Attorney General: (1) a certification that the State has developed a consolidated State plan that meets specified requirements and a specific description of the manner in which the grant will be used to carry out that plan; (2) a certification that any forensic science laboratory system, medical examiner's office, or coroner's office in the State that will receive any portion of the grant amount uses generally accepted laboratory practices and procedures, established by accrediting organizations; and (3) a specific description of any new facility to be constructed as part of the program, estimated costs of that facility, and a certification that the grant will not be used to fund more than 40 percent of such facility's total costs.

Prohibits the use of grant funds for any general law enforcement or non-forensic investigatory function. Limits facilities and administrative costs.

Sets forth provisions regarding record-keeping (and access to records and documents) and reporting requirements. Authorizes appropriations.