Forensic Science and Physical Evidence Questions and Answers

Answer: A

Unix systems maintain up to four date-time stamps.

The inode of a file in Unix file systems such as ext2 and ext3 holds the last access time (atime), the last modification time (mtime), the last inode change time (ctime), and the deletion time (dtime), which is set when the file is deleted. Hence up to four time stamps, which forensic examiners use to build timelines.

Three is the familiar number of MAC times on a live file, which is why it is a tempting wrong answer, but the question asks for the maximum maintained. Two or one are too few for any Unix file system.

Answer: A

BlackBerry was introduced by Research in Motion (RIM).

The Canadian company Research In Motion launched the BlackBerry 850, a two-way pager with email, in 1999. Its later BlackBerry smartphones, with their keyboards and secure push email, dominated corporate mobile communication in the 2000s, and RIM renamed itself BlackBerry Limited in 2013.

The Open Handset Alliance, led by Google, backs Android; IBM is a computing company; and HTC (High Tech Computer Corporation) is a Taiwanese phone maker. None of them created the BlackBerry.

Answer: C

Local binary pattern extracts texture features.

The local binary pattern (LBP) operator compares each pixel with its neighbours and records whether each neighbour is brighter or darker, giving a binary code. Histograms of these codes over regions of the face describe local texture, such as the patterns of skin, wrinkles and edges, and are widely used in face recognition because they tolerate changes in lighting.

LBP works on grey-level intensity, so it does not capture colour. It does not model the overall shape of the face, and it does not locate anthropometric landmarks such as the eyes and nose.

Answer: A

This mode is called creaky voice.

In creaky voice, also called vocal fry or laryngealisation, the vocal folds are short and slack and vibrate slowly and irregularly, so the individual pulses can be heard as a crackling or popping sound. It often occurs at the ends of utterances and is a feature examined in forensic speaker comparison.

A continuant is a sound that can be prolonged, such as a fricative or vowel. Cognates are pairs of sounds differing only in voicing, such as /p/ and /b/. Sibilants are hissing fricatives such as /s/ and /sh/. None of these is a mode of vocal fold vibration.

Answer: A

The Computerized Speech Lab is used to examine audio.

The Computerized Speech Lab (CSL), made by KayPENTAX, is a hardware and software system for recording and analysing speech. Forensic laboratories use it for speaker identification, producing spectrograms and measuring formants, pitch and other acoustic features of questioned and specimen voice recordings.

Video, images and documents are examined with other tools, such as video enhancement software, image analysis systems and the video spectral comparator for documents.

Answer: C

BEOSP stands for Brain Electrical Oscillation Signature Profiling.

It is a neuro-psychological technique, also called brain fingerprinting in the press, in which the suspect's EEG is recorded while statements about the crime are played. A distinctive response, said to show 'experiential knowledge' of the event, is looked for. It was developed in India by C. R. Mukundan and has been used by forensic laboratories in Gujarat and Maharashtra.

The other expansions each change one word: the signals are electrical (not 'electronic'), and the method produces a profile of the brain's responses, not a 'performance' or a 'program'.

Answer: B

The right to education is in Article 21A.

Article 21A was inserted by the Constitution (Eighty-sixth Amendment) Act, 2002. It makes free and compulsory education for all children aged 6 to 14 a fundamental right, in a manner the State may by law determine; that law is the Right of Children to Free and Compulsory Education Act, 2009.

The other articles deal with different rights: Article 14 with equality before the law, Article 22 with protection against arrest and detention, and Article 23 with the prohibition of traffic in human beings and forced labour.

Answer: A

The standard is ISO/IEC 27001.

ISO/IEC 27001 specifies the requirements for an information security management system (ISMS): how an organisation identifies risks to the confidentiality, integrity and availability of its information and puts controls in place. The 27000 family, including the privacy extension ISO/IEC 27701, covers information security and privacy protection.

The others are different standards. ISO/IEC 17025 sets the competence requirements for testing and calibration laboratories (the one forensic laboratories are accredited to). ISO 9000 is the quality-management family, and ISO 14001 covers environmental management systems.

Answer: B

At least 2 photographs are needed.

Photogrammetry recovers three-dimensional measurements from photographs. A single photograph fixes only the direction from the camera to each point, not its distance. Two photographs of the same scene taken from different positions give two lines of sight to each point, and their intersection fixes the point in space, the same principle as stereoscopic vision.

With 1 photograph, measurements are possible only with extra information such as a known reference scale in the same plane. More than two photographs (3 or 4) improve accuracy and coverage, but they are not the minimum.

Answer: B

The required details are (i), (ii), (iii), (iv), (vi).

A chain-of-custody record exists to show who collected each exhibit, what it is, where it came from and which case it belongs to, so that its integrity can be proved in court. It therefore records the exhibit number, a description of the item, where it was found, the name and signature of the person who collected it, and the case reference (FIR number, date and police station). Each later transfer is then signed and dated.

The name of the victim (v) is not part of the custody record; it may not even be known, and the evidence is tracked by its exhibit and case numbers. Every option that includes (v) is therefore wrong, and the option leaving out (iii) drops a required detail.