From Police Academy Training to Criminal Investigation: Strengthening Forensic Science in Policing

2.1. Remarkable Forensic Achievements in Police History Forensic science studies many disciplines, and it is a worldwide achievement of the human race. The history of forensic science can be traced back to ancient times [5], and it has assisted in many criminal investigations throughout its long history. The English word police was adapted from the Middle French police with the Latin origin politia [6]; thus, the police use of forensic science history in this article refers to the period from when the word police was first applied in France and other European countries to today’s policing. From the late 17th century to the early 18th century, French police and private investigation agencies started using ballistics, fingerprinting, footwear impression casting, and anthropometrics, benefiting from the innovations by Eugène François Vidocq [7]. After formal police departments were formed in England in the 19th century, forensic science became a practical part of policing. Rogues Gallery was used in 1858 instead of using posters or photos only, serving as a collection of criminal photographs used for identification; Alphonse Bertillon invented Bertillonage which utilized the body measurements for individual identification system in 1893 before fingerprinting time; the most popular practice was the fingerprint analysis method studied by pioneers, developed by Sir Edward Henry in the early 1900s and the Henry classification system is the standard for criminal fingerprint analysis in many countries until today [8]. One of the most important figures in the historic evolution of professional police, law enforcer August Vollmer, advocated using new technology for fighting crime such as fingerprinting, polygraphy, and crime laboratories in the early 1900s [4]. From the mid-1900s to 1980s, different fingerprinting techniques and fingerprint databases, blood presumptive tests, blood pattern analysis, sobriety testing, trace evidence identification, gunshot residue (GSR) detection, and drug presumptive testing were employed in the police investigation; from the mid-1980s, DNA as the most exciting innovation in the last century started playing as the most reliable scientific approach in the investigation [9]. In addition to other forensic innovations, digital forensics and forensic intelligence have been indispensable in modern policing since the Internet developed in the 1990s [10]. Law enforcement’s ability to gather evidence and construct cases based on digital footprints heavily depends on the digital forensics’ capacity to extract data, search for the digital device locations, recover deleted files, trace online activities, and more. Together with forensic intelligence, these two have significantly increased the capacity for investigation, particularly in a time when digital interactions are a part of daily life. 2.2. Current Status Different from the situation where general police practiced forensic science in early times due to the police developmental stage at that time, the current status of forensic science in policing has changed dramatically in recent years. 2.2.1. CSI Units and Personnel The most unforgettable case in recent CSI history was the murder of Nicole Brown Simpson and Ron Goldman in 1994. The suspect was not found guilty despite considerable evidence. The evidence searches, collection, and preservation errors in the CSI performance heavily impacted the trial of this case [11]. Investigators collected the evidence in this case from one of the largest police departments in the United States (US), the Los Angeles Police Department, and their roles were as detectives. The investigative failure of this case suggested significant shortcomings in the CSI process. After this incident, it was widely accepted by US police departments to form professional CSI units to undertake CSI duties. Currently, most large police departments in the US have a professional CSI unit to collect, document, and deliver crime scene evidence to the evidence unit in the department. The CSI unit within the police departments consists of sworn officer CSI investigators and/or civilian CSI investigators [12]. In the United Kingdom (UK), after the Metropolitan Police was formed, the Criminal Investigation Department (CID) became the branch of the police force with CSI functions in the UK and many Commonwealth nations. Transiting from CID officers in the late 1960s, civilian CSIs started replacing officers’ roles in the UK [13] and other police forces around UK continued this trend. In many Asian countries, the situation is different as CSI units mainly consist of officers. For example, in Japan [14], China [15], and Pakistan [16], the criminal investigation responsibility is uniquely assigned within police departments and criminal investigation sections are set up in police departments to carry out investigative duties. In Africa, it is also the police’s responsibility to conduct CSI; detectives or police officers are often the professionals to handle evidence [17,18,19], not trained CSI investigators. In the Republic of Colombia, criminal investigations were hampered by a lack of coordination in the gathering of evidence, which led to needless duplication of investigative efforts in the past; in light of the problem, the situation drastically changed, and the technical police are now the CSI personnel in criminal investigations [20]. In Mexico, before criminal justice reforms began in 2008, only investigative police under the control of the Public Prosecutor’s Office had investigative roles; the reforms granted all police at federal, state and municipal levels investigative function and also preserved the investigative powers of the Public Prosecutor’s Office [21]. 2.2.2. Crime Laboratory and Personnel The crime laboratory is another essential investigative service unit in police departments. Forensic scientists who specialize in different scientific disciplines analyze the evidence collected by the CSI units and other evidence gathered during the investigation process in crime laboratories. Modern crime laboratories often house forensic biology, forensic toxicology, trace evidence, and latent fingerprint disciplines. Some larger crime laboratories also analyze firearms and tool marks, fire and explosives, and digital evidence. The size of police departments is typically correlated with the capacity of crime laboratories. Although not always, some specialized forensic fields, including forensic engineering, forensic pathology, and forensic anthropology, are frequently used outside police departments. Usually, medical examiner or coroner offices, educational institutions, or the private sector houses these specialties. In the US, crime laboratories are established at the municipal, state and federal levels. The Federal Bureau of Investigation (FBI) crime laboratory, as a federal-level law enforcement crime laboratory, is the largest and most comprehensive forensic laboratory not only in the country but also in the world [22]. Like the US, most countries have developed and maintain their crime laboratories. In the 1990s, the British government established a system of the country’s crime laboratories, naming the service the Forensic Science Service (FSS) to serve the police service. FSS was assessed as no longer cost-competitive against private-sector rivals and terminated in 2012, making England and Wales the only parts of the world with a completely privatized forensic science industry [23]. In Japan [24] and Pakistan [25], the structures of criminal and death investigation systems are similar, mainly including police forensic science institutions for criminal investigation and university institutes of forensic-related disciplines; with the exception of how much private forensic laboratories have evolved after 2005, the state of crime laboratories in China is currently similar [26]. Throughout Africa, crime laboratories are mostly operated by police departments with some exceptions [27]. For example, a small number of forensic testing laboratories reside under the Department of Health in South Africa [28]. In Mexico, forensic experts with a solid knowledge of science interpret the evidence findings as assistants of the Public Prosecutor’s Office [29]. In the Republic of Colombia, crime laboratories are managed by the National Institute of Legal Medicine and Forensic Sciences, which reports to the Office of the General Attorney; the institute leads education and research in forensic medicine and forensic sciences in Colombia and Latin America [30]. The US Department of State’s Bureau of International Narcotics and Law Enforcement Affairs (INL) and the US Department of Justice’s International Criminal Investigative Training Assistance Program (ICITAP) provide forensic training to many neighboring countries, including the above two Latin American countries. 2.2.3. Forensic Science and Other Personnel in Criminal Investigation Procedures CSI and crime laboratories are indeed the most essential pieces in police use of forensic science. Nevertheless, the current status of forensic practice does not solely exist in traditional settings of CSI and evidence laboratory examinations. Forensic intelligence impacts crime prevention directly. The advantage of gathering and using data earlier in the criminal inquiry phase cannot be neglected by the police. Effective crime prevention by forensic intelligence exceeds all other forensic intervention results. One of the best practices of forensic intelligence in crime prevention is Interpol, the International Criminal Police Organization, and an intergovernmental organization, as a coordinating network that provides intelligence in preventing international crimes. As an example of this network, the Interpol Face Recognition System contains thousands of criminal facial images contributed from member countries, and this system has identified over one thousand criminals, persons of interest, or missing persons so far [31]. With the development of internet technology, the establishment of databases, the wide use of biometrics and digital surveillance, and the convenient information exchange through networking, many local police departments have developed forensic intelligence divisions to assist in crime prevention and criminal investigation. Basic investigative techniques are used daily by police officers in screening for suspicious crimes. Body-worn cameras, license plate readers, police drones, K9s, breathalyzers, portable substance detectors and explosive screening devices are, today, common police equipment. The investigative techniques based on the policing equipment are usually performed before or at the preliminary investigation phase by officers, not necessarily carried out by CSI personnel or forensic scientists. It follows then that the proactive use of investigative science is a basic skill for police officers in their daily duties in modern policing. Forensic communication bridges non-forensic officers and forensic service units to provide a convenient path for the investigative process, especially in follow-up investigations. After the evidence is submitted to crime laboratories, the detective must regularly follow up on the specific case. It is not uncommon that new evidence comes to investigative attention during the follow-up investigation. At this stage, normally, the CSI unit has completed its duty at the crime scene. Under these circumstances, besides evidence collection and preservation, the detective or other non-CSI/forensic officers superintend the communication with crime laboratories to get professional instruction on handling the new evidence. During the crime laboratory evidence examination, forensic scientists routinely take days or weeks to work on the evidence to provide professional opinions or issue reports. At this point, detectives actively collaborate with crime laboratories rather than passively awaiting results; they often communicate with crime laboratories and provide clues for them efficiently, using proper approaches and connecting with the network. It is commonly believed that when the case proceeds to prosecution and trial, police are free of forensic responsibilities because the investigative results have been concluded with their efforts. In criminal justice, common sense never equals justice. CSI personnel and forensic scientists are often called in the post-investigation procedures, particularly in the trial for expert witness testimony. The testimony is not just about stating what the results of forensic analysis were, but more about explaining to the judge and jury what those results mean and how the results were concluded. Plain language is used in testimony instead of forensic professional language; sometimes demonstrative methods such as photos, whiteboard drawing, or animation reconstruction are employed together with the testimony to help audiences better understand the evidence.