FORENSICS

Criminal investigations

Criminal investigations
Thermo Fisher Scientific's Nautilus LIMS is being used by the Forensic Science Service (FSS), a UK government-owned forensics company.

The increase in automation in forensic science in the last few years has led to a requirement for data management systems. Greg Blackman looks at the importance of LIMS in forensic laboratories

Scientific Computing World: February/March 2009

The clean-up surrounding large-scale disasters can involve massive amounts of manpower and resources, and take months or years to conclude. Victims from the attacks on the World Trade Center were still being identified as late as April 2008, more than seven years after the Twin Towers collapsed. The remains were identified through DNA analysis, and updated technology is being used to re-extract DNA to make new identifications.

The Brazilian TAM Airlines Flight 3054, which crashed on 17 July 2007 upon landing in São Paulo, and claimed the lives of all 189 people on board along with 10 employees working in the TAM Airlines building that it collided with, was Brazil’s largest aviation tragedy. The forensics team from the São Paulo Criminal Institute had to sift through 356,000 parts in order to identify the remains, which had been exposed to temperatures exceeding 2,000°C. Comparisons of DNA recovered from the wreckage with that from relatives of the deceased formed the basis of the identification.

A team from Applied Biosystems, led by Eduardo De Farias, set up its laboratory information management system (LIMS) SQL*LIMS to collate DNA profiles of victims and relatives. DNA typing involves scanning specific DNA regions, or loci, to build up a DNA profile of the individual. The DNA is extracted and amplified by polymerase chain reaction (PCR)-based methods to provide the DNA fingerprint. Comparing DNA fingerprints from two individuals can show whether or not they are related, and the DNA data from relatives and victims was fed into the SQL*LIMS to positively identify the remains.

‘One of the main challenges was to organise the process across the six laboratories involved, which covered two states in Brazil, and to do so under the intense pressure generated by the situation,’ explains De Farias. Standardised results, which followed the same procedure and stored the data by the same method, coordinated across each laboratory, were vital for the data to be meaningful as well as for final reports to be generated.

‘Identifying the victims of accidents such as this one is never easy,’ says De Farias. The identification process took approximately three months, with 80 per cent of the victims identified within the first month. Approximately 15 to 18 per cent of the remaining passengers were gradually identified over the course of the next month as further testing of remains was carried out, and three per cent of the passengers were not identified.

Victims of the World Trade Center attacks were still being identified in April 2008, almost seven years after the event.

DNA analysis is one of the main tools used in forensic science to identify individuals. Crime laboratories undertaking DNA typing are typically concerned with comparing DNA evidence with known standards. The evidence is DNA samples collected from a crime scene and these are cross-matched against DNA swabs taken from anyone connected to that scene, be that victims, defendants or elimination ‘knowns’. The elimination knowns can come from the victims’ relatives, for example, or, if it’s a shared house, from tenants. The comparisons are made, not only to generate and compile evidence against suspects, but also to exclude people from the investigation.

The Department of Forensic Medicine at the University of Copenhagen handles all requests for DNA profiling for the Danish authorities and uses a LIMS from global LIMS supplier LabWare. ‘The most important requirement is traceability, meaning being able to record all transactions made by both the system and by users,’ states Lynge Christiansen, responsible for the development of the LIMS at the Department of Forensic Medicine. Christiansen says that, without the LIMS, it would be impossible to adhere to quality standards and the department would be reliant on databases and a paper trail.

LabWare designed various modules to easily accommodate the requirements of forensic science. ‘Forensic laboratories have certain requirements that are often not found in other types of laboratory,’ notes John Gabathuler, director, industrial and environmental at LabWare. ‘At the same time, some modules which were designed for other types of laboratory lend themselves well to forensics.’

‘One of the key requirements for a forensic LIMS includes functionality that supports compliance with the relevant regulatory requirements,’ comments Steve Kemp, informatics channel manager at Thermo Fisher Scientific. The most widely referred to standard is ISO/IEC/EN 17025 General Requirements for the Competence of Calibration and Testing Laboratories.

LIMS enables forensic laboratories to meet the demands of accreditation audits. ‘It [LIMS] ensures that we can track any given sample or case at any given time and so maintain the auditing that is crucial to the ISO 17025 standard,’ says Christiansen.

Christiansen notes that the LIMS is having a larger and larger impact on the work carried out. ‘This March we are launching the next phase or our LabWare programme and this phase encompasses the entire life cycle of one of our sections. We are going to use the LIMS, not only as a system for managing laboratory information, but in essence as a production management system.’

LIMS can also serve to manage the workflows of staff: the forensic science division of the Maryland State Police uses LIMS supplied by global company Starlims, to coordinate workflows across the various sections and laboratories that make up the division. These include firearms/tool marks, questioned documents, latent prints, chemistry and toxicology, the crime scene unit, which works out in the field, photography, trace evidence and the biology laboratories, which are split up into trial case work, investigative case work and the CODIS group. The operation also has a central receiving unit that manages the workload going in and out, and allocates the work to each section or analyst.

‘The LIMS is used to track evidence as it passes through the various stages in the chain of custody and also serves as a notification system,’ explains Captain David Hopp of the forensic science division. For instance, the LIMS will notify the biology department supervisor of cases pending and allows the supervisor to assign work to analysts in the laboratory. Alerts from LIMS will notify the analyst that there is evidence requiring analysis. A list of assays, from which an analyst may choose, is also captured in LIMS. ‘All evidence for each case is stored in LIMS as a complete package and it’s possible to track individual pieces of evidence as they are assigned and pass through the chain of custody,’ Hopp says.

The system is set up in order to grant different levels of access to different users, so that an analyst, for example, would only have access to their particular module and read only rights in others whereas an administrator would have access over the entire system. ‘This is a key advantage of the system, as eventually external users can be granted access to certain areas on a limited basis to retrieve results,’ says Hopp. State attorneys, for instance, can have access to information on cases as well as the approximately 150 agencies for which the forensic science division carries out work.

George Duncan, DNA unit manager at the crime laboratories at Broward Sheriff’s Office, comments: ‘LIMS answers all the questions that forensics demand: namely traceability, i.e. where is the sample; and will it integrate with the instrumentation?’ Broward Sheriff’s office covers Broward County, Florida, an area populated by 1.7 million people including Fort Lauderdale, and the crime laboratories use SQL*LIMS from Applied Biosystems.

The crime laboratories are primarily concerned with DNA analysis. ‘Each sample is designated with a number and moves from tubes to 96-well plates to generate the profile, with LIMS tracking the sample at every step and integrating directly into the instrumentation,’ explains Heather LaSalle, DNA analyst at Broward Sheriff’s office. DNA profiles can then be analysed against CODIS (Combined DNA Index System), a national US DNA database created by the FBI, to generate matches and potential suspects.

One of the most important resources for a DNA forensics laboratory in the US is CODIS, but only certain profiles can be entered into CODIS. The LIMS allows the laboratory to store and maintain its own database of profiles it needs for its own use. ‘LIMS has the flexibility to do this, and DNA profiles could be cross-matched against CODIS and against the local database stored in LIMS,’ notes Duncan.

The forensic science laboratories of the Maryland State Police is using LIMS software to track samples and manage workflows. Image courtesy of Starlims.

A scandal involving the Baltimore Police Department in which unknown profiles – suspects who it was assumed were still at large – turned out to be contamination from staff, brought into question the DNA evidence provided for those cases. ‘The techniques involved in amplifying DNA are extremely sensitive,’ notes Duncan and it’s in this type of scenario where an internal database of staff DNA profiles could have avoided the mistake.

‘The most important thing for a DNA forensics laboratory is to make sure you get the right answer and that you don’t falsely include or falsely exclude someone from the case,’ states Duncan. ‘LIMS is exacting enough, but also flexible enough to give a good handle on the data, which means the analysts are less likely to make inadvertent errors.’

‘Data management in forensic science is not just one single issue,’ comments Kemp of Thermo Fisher Scientific. ‘Although some aspects are common to all, differences in working practices, differences in criminal justice systems and differences in the relationship between the laboratory organisation and its customers (police internal, police external, independent contract etc.) all have a significant impact.’

Thermo Scientific’s Nautilus LIMS product is currently being used by the Forensic Science Service (FSS), a UK Government-owned company providing forensic science to international law enforcement agencies, world judiciary systems and private sector customers. In a typical year, the FSS handles more than 100,000 criminal cases, involving some 2,600 staff in 14 facilities across the UK. The FSS was instrumental in the establishment of the world’s first DNA database, the UK National DNA Database (NDNAD), and has recently launched a rapid DNA profiling service that can produce results in less than 24 hours. This is available to police forces across the country and enables the express processing of priority DNA submissions.

Duncan of Broward Sheriff’s office notes that the National Institute of Justice, the research, development, and evaluation agency of the US Department of Justice, gives priority in funding to laboratories using a LIMS, which is a big incentive for laboratories to implement the systems.

Christiansen of the University of Copenhagen says that the amount of forensic work has increased dramatically and work processes have become more and more automated. ‘The consequence has been that we now have far more data to collect and maintain,’ he says. LIMS is able to interact with laboratory equipment and improves efficiency of preparing files and collecting results.

Currently, the forensic science division of the Maryland State Police is still testing its system, with two users per discipline working together to address any problems experienced with the new technology. This means the analysts are effectively doing twice the work, as traditional working procedures are carried out in parallel to using the LIMS. ‘LIMS is one of those technological changes that have a difficult initial period of testing, but will eventually improve the management of workloads,’ says Hopp of Maryland State Police. ‘The workload for a number of disciplines within the forensic science division has increased and LIMS is a necessary technological advancement in managing that.’

Explosives database

A team at University of Rhode Island in the US has developed a database of explosives intended for use by forensic laboratories. Professor Jimmie Oxley, heading up the team, compiled the database to act as a useful reference point for forensic laboratories and counter terrorism agencies when identifying explosive material.

‘Prior to this database, laboratories would have to create their own library of spectra when identifying explosive material,’ says Oxley. ‘The aim of the project is to allow users to upload a spectrum and match it against a spectrum on the database.’

Identification methods for materials generally rely on spectroscopy, although for energetic materials, calorimetry (DSC), establishing the heat release, is also essential. The database includes spectrum from various instruments – infrared, Raman, mass spectrometers, and DSC – as well as remarks as to protocols for synthesis and disposal of common military, commercial and homemade explosives. The database utilised software from Toronto-based ACDLabs to capture the spectrum. ‘The software from ACDLabs had to be multi-instrument compatible,’ notes Oxley.

The project was funded by the Oklahoma City Memorial Institute for the Prevention of Terrorism (MIPT); and Oxley feels that, with further development, the database will provide a comprehensive resource on explosives for forensic laboratories.