Genetic Testing

DNA testing in the police department

ホロスコープや占星術を用いた親子鑑定

↓今すぐDNA出生前親子鑑定を予約する↓

簡単WEB予約はこちら

The time required for a DNA analysis performed by the police depends on the type of analysis, the urgency of the case, the technology used, and the processing capacity of the laboratory. Below is an overview of the general process for police DNA testing and the time it takes to complete a DNA analysis.

Purpose of DNA Analysis

DNA testing by the police is used primarily for the following purposes

  • Criminal Investigation: Identification of perpetrators from DNA samples such as blood, saliva, skin cells, hair, etc. left at crime scenes.
  • Identification: Used to verify the identity of missing persons or persons killed in accidents, disasters, incidents, etc.
  • Paternity: DNA testing to confirm legal parent-child relationships in inheritance and custody disputes.

2. time for DNA analysis (for police)

The time it takes for the police to conduct a DNA analysis varies greatly depending on the urgency and complexity of the case.

  • For urgent cases: In cases of serious crimes (e.g. murder or sex crimes) or disappearances that are deemed urgent, expert testimony may be obtained in a matter of days to a week. Priority is given to cases with important evidence, especially if the evidence is critical to the progress of the case.
  • For regular cases: these may take several weeks or months depending on the non-urgent nature of the case and the priority of other cases. This depends on the capacity of the police appraisal agency and other appraisal tasks.
  • For Paternity Tests: DNA testing to confirm legal paternity is usually not urgent, even when performed by the police, and can take one to two months.Paternity testing, like any other legal matter, is affected by the order of processing and the necessary paperwork.

3. the DNA analysis process

DNA testing by the police involves the following steps

  1. Sample Collection: Collect samples such as blood, saliva, and skin fragments from the crime scene.In the case of paternity testing, samples are collected from oral mucosa and blood.
  2. DNA extraction and purification: DNA is extracted from the collected sample and purified for testing by removing impurities.
  3. PCR (polymerase chain reaction): amplifies a specific portion of DNA and increases it to an amount suitable for analysis.
  4. Genotyping: Analyze amplified DNA to identify genotypes for person identification.
  5. Matching: The resulting genotypes are matched against suspects and existing databases. In the case of paternity testing, DNA patterns of the parent and child are compared.
  6. Result Report: A final report is prepared and submitted to the responsible department.

Factors affecting appraisal time

  • Urgency: Priority depends on the importance and urgency of the case. Urgent cases are processed faster, while regular cases may have a waiting list.
  • Sample Condition: If the DNA sample is degraded or very low in quantity, the analysis may take longer. Also, if contamination occurs during sample collection, retries may be required, which may increase the time.
  • Complexity of the case: criminal investigations can involve multiple samples and can be time consuming if additional testing is required to match each one.

5. Time saving by the latest technology

Recently, new technologies such as next-generation sequencing (NGS) have been introduced to allow DNA analysis to be performed more quickly than in the past. This has increased the number of urgent investigations for which results can be obtained in a few days, but standard tests still typically take several weeks.

Summary

The time required for DNA testing by the police depends on the urgency of the case, the processing capacity of the laboratory, and the condition of the sample. In urgent cases, results may be available within a few days to a week, but usually take several weeks to several months. Although technological advances are speeding up the process, processing time varies depending on the complexity of the case and its priority with other cases.

医師監修 監修日：2024年9月17日

岡 博史 （おか ひろし）

医師・医学博士 ／ ヒロクリニック統括院長

YouTubeチャンネルなどを通じて、遺伝子やNIPT（新型出生前診断）についてわかりやすく発信しています。

略歴

  • 1996年 慶應義塾大学医学部 卒業
  • 2004年 慶應義塾大学 医学博士号 取得
  • 2005年 慶應義塾大学 皮膚科学教室 助手
  • 2008年 ヒロ皮フ形成クリニック 開業
  • 2009年 医療法人社団福美会 理事長
  • 2015年 医療法人社団福美会 理事

資格・所属

  • CAPラボディレクター
  • 日本皮膚科学会 皮膚科専門医
  • 日本医師会 産業医
  • 東京衛生検査所 指導監督医

発信・関連リンク

この記事は、 ヒロクリニックNIPPTの編集・監修体制 にもとづき、資格を持つ医師が内容を確認しています。

医師監修 監修日：2024年9月17日

堤 修一 （つつみ しゅういち）

医師・医学博士 ／ ヒロクリニック博多駅前院 院長

略歴

  • 1993年 東京大学医学部医学科 卒業
  • 2016〜2019年 東京大学先端科学技術研究センター 准教授

発信・関連リンク

この記事は、 ヒロクリニックNIPPTの編集・監修体制 にもとづき、資格を持つ医師が内容を確認しています。

参考文献

  1. Jeffreys AJ, Wilson V, Thein SL. Individual-specific 'fingerprints' of human DNA. Nature. 1985 Jul 4;316(6023):76-9.
  2. Gill P, Jeffreys AJ, Werrett DJ. Forensic application of DNA 'fingerprints'. Nature. 1985 Dec 12;318(6046):577-9.
  3. National Police Agency. About DNA Profiling [Internet]. Tokyo: National Police Agency; [cited 2023 Oct 24].
  4. National Research Institute of Police Science. Reports of the National Research Institute of Police Science [Internet]. Kashiwa: National Research Institute of Police Science; [cited 2023 Oct 24].

Latest Articles

Supervisor of the article

Dr. Hiroshi Oka

Director of CAP Laboratory

Graduated from Keio University, Faculty of Medicine

Doctor of Medicine

Medical Doctor