Which of the following prevents contamination of evidence?
Asked by: Dr. Davion Nienow | Last update: July 9, 2025Score: 4.6/5 (40 votes)
Collect evidence correctly, preserve each specimen separately, use and change gloves often, avoid coughing or sneezing during the collection, use appropriate tools such as cotton-tipped applicators, sterile water, cardboard swab boxes, separate paper bags, and envelopes to prevent cross-contamination of samples ...
How can we prevent contamination of evidence?
Wear double gloves and change the top pair often. Use disposable instruments or clean reusable instruments thoroughly before and after each sample is taken to prevent contamination. Air-dry wet evidence thoroughly before packaging to prevent mold from forming. To prevent degradation, place evidence in new paper bags.
Which of the following prevents contamination of evidence: encryption, read blockers, write blockers, disk wipers?
Hardware Write Blockers
By intercepting write commands at the hardware level, these devices ensure that the original evidence remains unaltered during the investigation.
What causes contamination of evidence?
In general, the grater number of personnel at the scene, the more likely it is that the scene/evidence will be contaminated. Scene personnel can deposit hairs, fibers or trace material from their clothing or destroy latent footwear or fingerprints.
How we can control the contamination of digital evidence?
Finally, keep in mind that you should always package and label digital evidence properly and securely before transferring it for further processing or analysis. This helps prevent the contamination of data from external sources and ensures the integrity of your findings.
A Body of Evidence: Measures to Improve Collection & Reduce Contamination
How to protect digital evidence?
For the digital preservation of evidence, this involves making copies of all relevant data storage devices. In addition, the digital forensic expert should identify hidden data areas and restore deleted data. Data downloaded from the data storage (data leakage) should be documented.
What is cross-contamination in forensic science?
Cross-contamination - The unwanted transfer of material between two or more sources of physical evidence. For example, improperly collecting biological evidence such as blood could lead to one sample mixing with another sample and contaminating both.
What are the 3 causes of contamination?
- poor waste management.
- poor construction, industrial or agricultural practices.
- illegal dumping or unsafe storage of harmful products.
How to prevent contamination to DNA sampling?
To avoid human contamination, all individuals who handle DNA samples should wear gloves, masks, and other protective equipment to reduce the chance of transferring their DNA onto the sample. Additionally, samples should be collected and stored in a way that minimizes the chance of contact with human DNA.
What is an example of evidence contamination?
Tools can easily transfer DNA from one crime scene to another. Fingerprint brushes, for example, can retain the DNA they pick up and create contaminated evidence. In order to ensure there will not be a transfer of DNA on brushes, they should not be reused.
What is a write blocker in digital forensics?
Definitions: A device that allows investigators to examine media while preventing data writes from occurring on the subject media. A tool that prevents all computer storage media connected to a computer from being written to or modified.
Which of the following does encryption protect you against?
Encryption is used to protect data from being stolen, changed, or compromised and works by scrambling data into a secret code that can only be unlocked with a unique digital key.
Which tool can be used to protect the all data stored inside a hard disk?
BitLocker is designed to work best with a Trusted Platform Module (TPM) that stores the disk encryption key. TPM is a secure cryptoprocessor that checks whether the encrypted data is being accessed with the right device.
What prevents contamination?
To prevent this: Wash hands with soap and hot water before and after handling food, and after using the bathroom, changing diapers; or handling pets. Use hot, soapy water and paper towels or clean cloths to wipe up kitchen surfaces or spills. Wash cloths often in the hot cycle of your washing machine.
What are the necessary precautions for preservation of evidence?
The five steps recommended by the Federal Bureau of Investigation for collecting and preserving evidence are (1) obtaining it legally; (2) describing the evidence in detailed notes; (3) identifying it accurately and positively; (4) packaging it properly for identification, storage, or shipment to the laboratory; and (5 ...
What are three things forensic detectives should do while collecting DNA evidence to avoid contamination?
Avoid talking, sneezing, and coughing over evidence. Avoid touching your face, nose, and mouth when collecting and packaging evidence. Air-dry evidence thoroughly before packaging. Put evidence into new paper bags or envelopes, not into plastic bags.
How to prevent evidence contamination?
- Wear gloves and change them often.
- Use disposable instruments or clean them thoroughly before and after handling each sample.
- Avoid touching the area where DNA may exist.
How can we prevent sample contamination?
Wearing gloves, hairnets, pants, lab coats, and close-toed shoes. This equipment protects both the person wearing it and reduces contamination. Personnel should never reuse disposable gloves and they should always change them when moving between samples to further reduce the risk of contamination.
How do you remove contaminants from DNA?
- Phenol-Chloroform Extraction. Phenol chloroform extraction, normally followed by ethanol precipitation, is the traditional method to remove protein from a DNA sample. ...
- Ethanol Precipitation. ...
- Silica Column-Based Kits. ...
- Anion Exchange. ...
- Magnetic Beads.
What activity would best prevent contamination?
The easiest way to prevent cross contamination is by properly washing hands before cooking and in between tasks and by keeping raw foods and ready to eat foods separated. Use separate equipment for each type of food.
What are the 3 types of contamination you must prevent?
Traditionally, we taught that there were three types of food contamination: physical, chemical, and microbial (sometimes called biological). These days, we add a fourth type: allergenic. All food is at risk from these four types of contamination.
How to prevent microbiological contamination of food?
always wash hands thoroughly before and after handling raw food, including vegetables and fruit. keep unwashed raw fruit and vegetables separate from ready-to-eat food during storage and preparation. where possible use a separate chopping board, knives and utensils for raw and cooked food.
What is the contamination of DNA evidence?
Contamination Issues
This can happen if someone sneezes or coughs over the evidence, or if the person collecting the evidence touches his/her mouth, nose, hair, or any other part of his/her body, and then touches the area that may contain the DNA to be tested.
What are the 7 steps of investigation?
- Secure the Scene.
- Separate the Witnesses.
- Scan the Scene.
- See the Scene.
- Sketch the Scene.
- Search for Evidence.
- Secure and Collect Evidence.
How can evidence be biased in criminology?
For example, if one piece of forensic evidence (biased or not) is known to other forensic examiners who are analyzing other forensic evidence, then their examination may be affected and biased by their knowledge of the results of the other piece of evidence (for example, a forensic examiner looking at bite marks may be ...