A state draft report recommends building a TBI Crime Lab in Chattanooga as one part of the effort to reduce time in examining evidence in criminal cases.
For many years, law enforcement officers from the Chattanooga area have had to shuttle evidence - mainly to Nashville.
There are existing crime labs also in Knoxville and Jackson. The draft report from TACIR (Tennessee Advisory Commission on Intergovernmental Relations) says all those labs are running out of space and need to be expanded.
The Chattanooga lab would be smaller than the other three and focused on drug-related evidence and toxicology.
According to the study, "Adding new capacity in Chattanooga would relieve pressure on the Knoxville lab, improve regional access, and reduce the need to transfer evidence across the state. Although recent state investments have led to improvements in capacity and forensic evidence turnaround times, persistent backlogs continue to delay investigations and court proceedings across Tennessee, and the state’s projected population growth suggests that its current crime lab capacity will not be sufficient to meet future needs."
The draft report says:
In recent years, the state has increased its testing capacity by hiring additional scientists. TBI operates three forensic crime labs—one in Jackson, Knoxville, DRAFT TACIR draft 2 and Nashville. Over the last four years, the General Assembly has appropriated funding for 50 new forensic scientists between these labs. As of January 2025, TBI has filled 49 of these positions. The General Assembly also approved five additional positions in digital forensics. In its 2024 annual report, TBI found improvement in turnaround times from hiring and training new employees. Although turnaround times for some testing categories have improved, other categories have not, and on top of that, demand for testing continues to increase: • For example, while turnaround times for sexual assault cases have decreased from 45 weeks in August 2022 to 14 weeks in December 2024, turnaround times for violent forensic biology evidence increased from 24 weeks in January 2022 to 37 weeks in January 2025, and times for firearms analysis increased from 38 weeks to 67 weeks in the same period. • Regarding increases in testing requests, demand for all forensic biology tests increased 7% statewide over the past three years, and the total number of requests for all testing categories at TBI’s Jackson and Knoxville crime labs increased by 17% and 4%, respectively, between 2023 and 2024.
Tennessee’s comparatively high rates of crime and population growth mean that demand for testing is likely to continue to increase. Tennessee’s violent crime rate in 2023 was well above the national rate, but even if crime rates were to decrease in the future, projections for the state’s population growth suggest the volume of cases and evidence that needs to be tested could continue to grow.
The Boyd Center for Business and Economic Research projects there will be approximately one million more Tennessee residents by 2044. Ultimately, the Comptroller’s 2024 performance audit of TBI found that “management faces additional backlog challenges,” specifically within the Forensic Services Division’s Firearms and Toolmark Identification Unit and Forensic Biology Unit, despite recent hiring, indicating that additional investments in capacity remain essential to meet the state’s growing forensic needs. Lack of physical lab space is now the primary factor constraining the capacity of TBI’s labs. The Comptroller’s 2024 performance audit identified workspace expansion as the next significant challenge in TBI’s Forensic Services Division because adding more staff means needing more space to accommodate them.
And according to TBI’s quarterly report to the General Assembly in January 2025, while the Nashville lab may be able to accommodate one additional forensic biology scientist, the Jackson and Knoxville labs are currently at capacity.In March 2024, TBI completed a real estate strategic plan that outlines future expansion goals, including expansion of the Jackson lab, renovation and expansion of the Nashville lab, plans for a new, larger lab in Knoxville to replace the current one, and the establishment of a smaller lab in Chattanooga. According to TBI, the additional capacity will aid it in reducing turnaround times to its goal of 8 to 12 weeks for all testing.
Although funding for the future projects in Nashville, Knoxville, and Chattanooga has not yet been secured, the expansion of the Jackson lab is planned to begin in 2025. Commission staff analysis supports the need for additional lab space in each grand division: • West: The Jackson lab, completed in 2021, has already outgrown its current space, and from 2023 to 2024, the lab experienced the highest percentage increase in forensic evidence requests among the three TBI labs. Because Shelby County submits the largest volume of firearms requests to the Jackson lab, it raises the possibility that a new lab in Memphis might be warranted. But building a new lab would likely cost between $52 million and $66 million - not including the cost of hiring personnel, training, utilities, equipment, and other unexpected expenditures. From conception to opening, the Jackson lab took approximately six years, and according to MetroNashville - the only local government to operate its own crime lab in the state - constructing a new full-service lab can take 5 to 10 years. Given these costs and timelines, to better serve Memphis and the whole of West Tennessee, another approach is for TBI to embed a dedicated firearms analyst to work solely on Memphis cases at the expanded Jackson lab. States like Louisiana have used this approach successfully, and stakeholders in Memphis and at TBI are open to it.
• Middle: The TBI Nashville lab receives the most forensic evidence requests of any of the three labs, as it offers all forensic services. It also has a heavier caseload in forensic chemistry and both drug and alcohol toxicology than most crime labs across the country. Several counties, like Rutherford and Wilson, have high volumes of requests for toxicology and forensic chemistry tests, which are critical to managing drug-related evidence and DUI cases in Middle Tennessee’s growing population centers. Turnaround times at this facility are among the highest statewide, particularly in forensic biology.
• East: The Knoxville lab has reached its physical limit, and TBI cannot add additional square footage on the existing property. The lab doesn’t have an in-house firearms unit despite high demand from regional stakeholders, which contributes to longer turnaround times and added strain on the firearms unit of TBI’s other labs. Additionally, southeast Tennessee has a need for forensic chemistry and toxicology testing. Hamilton and Knox counties are among the highest requestors for toxicology in the state, with Knox County having the most toxicology requests in 2024. Adding new capacity in Chattanooga would relieve pressure on the Knoxville lab, improve regional access, and reduce the need to transfer evidence across the state. Although recent state investments have led to improvements in capacity and forensic evidence turnaround times, persistent backlogs continue to delay investigations and court proceedings across Tennessee, and the state’s projected population growth suggests that its current crime lab capacity will not be sufficient to meet future needs. Ultimately, without confronting the constraint of limited lab space, the state’s efforts to further improve forensic evidence processing and public safety will be hindered.
For these reasons, the commission recommends that the state increase crime lab capacity in each grand division—in line with TBI’s 2024 real estate strategic plan—specifically by expanding the existing Jackson and Nashville labs, replacing the existing Knoxville lab with a larger lab with capacity for firearms testing, and adding a smaller, focused lab in Chattanooga for drug-related evidence and toxicology. Additionally, the commission recommends that TBI and the city of Memphis enter into an agreement for a firearm analyst in the Jackson lab dedicated to Memphis cases and that expansions at the Nashville lab focus on the most overburdened disciplines—like forensic chemistry and toxicology. In addition to expanding lab space, the state can do several things to help reduce turnaround times at its existing laboratories. Several practices to reduce workloads and improve productivity can support crime labs while the state undertakes long-term expansions of its facilities. These include using process improvement methodologies to increase lab efficiency, supporting the use of rapid DNA testing, and developing partnerships to share resources. Given the ongoing demand for high quality analysis and limited resources, crime lab staff often seek ways to operate more efficiently. The United States Department of Justice’s National Institute of Justice recommends that forensic DNA labs use process improvement tools - like Lean Six Sigma (LSS) and process mapping - to improve their performance by streamlining operations and reducing waste. Forensic laboratories in other states have used LSS and similar methodology and report improvements in backlogs and turnaround times. Crime lab leadership in Tennessee say these process improvement tools can be beneficial, but they caution that forensic labs face unique challenges, like highly varying evidence types, and the tools and principles need to be applied and adapted carefully.