e. Other types of identification evidence

e. Other types of identification evidence

A few other identification (non-visual) methods are potentially admissible as identification evidence.

Voice identification

In HKSAR v Yeung Ka Ho (2013) 16 HKCFAR 609, the CFA hold that voice identification evidence is admissible that the identity of participants and the timing and circumstances of a recorded conversation can be proved by reference to the recording content, such as where the statement maker is unknown or unavailable, or the content of the recording can be placed in a context of known facts to establish the time and place of the conversation. Similarly, the identity of a speaker may emerge from what is said. Statements revealing the facts or knowledge that only an offender could know frequently can lead to identification.

It is important to note that identity cannot be only proved by voice identification, but also by recording content and context.

Fingerprint Evidence  

Fingerprint evidence is a reproduction of the friction ridges of a person’s fingers on a surface. Due to the unique nature of each person’s fingerprint, identification is possible by comparing the fingerprints on an object with the person’s fingerprints.

In R v Buckley [1999] EWCA Crim 1191, the English CA laid down the following principles on the admissibility of fingerprint evidence:

1. Expert witnesses’ expertise and experience;
2. The number of similar ridge characteristics, and if there are fewer than eight similar ridge characteristics, it would be exceptional for a judge to admit such fingerprint evidence based on his/her discretion;
3. Whether there are dissimilar characteristics;
4. The size of the print relied on;
5. The quality and clarity of the print relied on, taking into account any finger injuries.

Section 59 of the Police Force Ordinance (Cap. 232) grants powers on the Hong Kong Police Force to extract fingerprints. A police officer can, pursuant to section 59(1), take the fingerprints of an arrested person. However, the fingerprints should be destroyed in case of a person being discharged or acquitted after trial or appeal. 

DNA Evidence

The utilization of DNA in criminal cases has risen in recent years. When an individual touches an object or surface, they may leave behind body fluids or tissues containing their DNA. Matching the DNA from the crime scene with the individual's DNA allows for identification. However, this process is more intricate than fingerprint analysis. While fingerprints are unique, a person's DNA characteristics may match with a small portion of the population. Therefore, DNA evidence has probative value only if there has already been other evidence. 

The cogency of DNA evidence makes it particularly crucial that: (a) DNA testing is rigorously conducted to prevent the risk of laboratory error; (b) the method of DNA analysis and the basis of subsequent statistical calculation should, as far as possible, be transparent to the defence; and (c) the real import of the resultant conclusion is accurately and impartially explained to the jury.