United States forensic DNA databases: NDIS, SDIS, and FOIA datasets

This record contains three datasets describing U.S. forensic DNA databases: an NDIS time series (2001–2025), a 2025 SDIS state cross-section, and 2018 FOIA demographic tables. The National DNA Index System (NDIS) dataset is a longitudinal series reconstructed from archived FBI webpages, providing jurisdiction-level counts of offender, arrestee, and forensic profiles, along with the number of participating laboratories and investigations aided. The State DNA Index System (SDIS) dataset was compiled through a systematic search of state repositories and statutes conducted in 2025, capturing reported totals, disaggregated counts where available, arrestee-collection status, familial-search policies, and statutory references across all 50 states. The FOIA dataset contains demographic summaries from seven states released in 2018 (Murphy & Tong, 2020), standardized into a tidy long format with race and gender categories harmonized to U.S. Census classifications and provenance flags distinguishing reported from calculated values. All three datasets are provided as machine-readable CSVs with accompanying data dictionaries and reproducibility notebooks. A provenance manifest documents raw source locations (e.g., Internet Archive snapshots for NDIS, state webpages for SDIS), ensuring transparency even where redistribution of source files is not possible. Figures used in the associated manuscript are also included to illustrate data structure and validation. Note: The largest folder is the NDIS timeseries snapshots. This is zipped within the zipped folder (i.e. nested) so if you unzip the main folder, you will still have to unzip the ndis folder. This is to prevent opening over 10k files unwittingly if you do not immediately need this raw data. Please see the README.md for a description of the file and folder structure. Also the data is available in the GitHub repository and the accompanying Quarto website if you would like to browse without downloading.本数据集套件包含三套用于描述美国法医DNA数据库的数据集：分别为国家DNA索引系统（National DNA Index System, NDIS）时间序列（2001—2025年）、2025年州DNA索引系统（State DNA Index System, SDIS）州级横截面数据集，以及2018年《信息自由法》（Freedom of Information Act, FOIA）人口统计表格数据集。 国家DNA索引系统（NDIS）数据集为纵向时间序列，通过归档的联邦调查局（Federal Bureau of Investigation, FBI）网页重构而来，提供了按司法管辖区划分的罪犯、被捕者及法医DNA档案数量，同时包含参与实验室数量及协助调查的相关统计数据。 州DNA索引系统（SDIS）数据集于2025年通过系统性检索各州DNA数据库及相关法规汇编而成，涵盖全美50个州的报告统计总量、可获取的细分计数、被捕者样本采集状态、家族搜索政策及法规引用信息。 《信息自由法》（FOIA）数据集包含2018年公开的7个州的人口统计摘要（Murphy & Tong, 2020），经标准化处理为整洁的长格式数据，其中种族与性别分类匹配美国人口普查局的分类标准，并通过来源标记区分报告值与计算值。 三套数据集均以机器可读的逗号分隔值（Comma-Separated Values, CSV）格式提供，附带数据字典与可复现性笔记。数据集溯源清单记录了原始数据源的存储位置（如NDIS的互联网档案馆（Internet Archive）快照、SDIS的州政府网页），即便无法重新分发源文件，也能保障研究的透明度。相关手稿中使用的图表也一并提供，用于说明数据结构与验证过程。 注意：最大的文件夹为NDIS时间序列快照文件夹。该文件夹嵌套在主压缩包内（即二级压缩），因此解压主文件夹后，仍需单独解压ndis文件夹。此举旨在避免用户在无需立即获取原始数据时，意外打开超过1万个文件。如需了解文件与文件夹结构的详细说明，请参阅README.md文档。若希望无需下载即可浏览数据集，可访问本项目的GitHub仓库及配套Quarto网站。