1. Forensic Evidence and Crime Investigation

2. 2 Objectives Understand what constitutes a crime and identify categories of crime Understand law enforcement’s authority to investigate information warfare and terrorist threats to national security Explain the different types of evidence Identify what affects the admissibility of evidence

3. 3 Objectives (Cont.) Identify how electronic evidence differs from physical evidence Identify what digital forensics tools and techniques can reveal and recover Explain the process of discovery and electronic discovery

4. 4 Introduction Criminal investigations involve the analysis of ballistic or bloodstain patterns, gunpowder residue, tire tracks, fingerprints, or evidence left by electronic devices. E-evidence is the digital equivalent of the physical evidence found at crime scenes.

5. 5 Introduction (Cont.) The expansion of the Internet provides countless opportunities for crimes to be committed Digital technologies record and document electronic trails of information that can be analyzed later  E-mail, instant messages (IM), Web site visits  PDAs, iPods, smart phones, cookies, log files etc.

6. 6 Introduction (Cont.) This chapter introduces:  Legal foundations for recovering evidence  Foundations for examining computer forensic evidence  Crime and principles of evidence  Admissibility of evidence  Proper evidence collection and handling procedures

7. 7 Basics of Crimes Early cases that illustrate the importance of knowing the law regarding computer crimes  Robert T. Morris Jr. (Morris worm)  Onel De Guzman (Lovebug virus) Computer crimes can be prosecuted only if they violate existing laws

8. 8 Morris Worm and Lovebug Virus Morris was charged with violation of the Computer Fraud and Abuse Act (CFAA) Morris sentenced to 3 years probation, 400 hours of community service, and a $10,500 fine Lovebug virus did $7 billion in damage in 2000 De Guzman released because no law in the Philippines made what he had done a crime

9. 9 Definition of Crime A crime is an offensive act against society that violates a law and is punishable by the government Two important principles in this definition:  The act must violate at least one criminal law  It is the government (not the victim of the crime) that punishes the violator

10. 10 Crime Categories and Sentencing Crimes divided into two broad categories:  Felonies—serious crimes punishable by fine and more than one year in prison  Misdemeanors—lesser crimes punishable by fine and less than one year in prison Sentencing guidelines give directions for sentencing defendants  Tougher sentencing guidelines for computer crimes came into effect in 2003

11. 11 Cybercrime Categories The terms computer crime, cybercrime, information crime, and high-tech crime are used interchangeably Two categories of offenses that involve computers:  Computer as target—computer or its data is the target of the crime  Computer as instrument—computer is used to commit the crime

12. 12 Cybercrime Statutes and Acts Statutes are amended to keep pace with cybercrimes  CFAA (Computer Fraud and Abuse Act) of 1984 Amended in 1986 to include stiffer criminal penalties (only government and financial institutions) Revised in 1994 to include a civil law component New acts are passed to control cybercrime  CAN-SPAM Act of 2003

13. 13 Civil vs. Criminal Charges Civil charges are brought by a person or company  Parties must show proof they are entitled to evidence Criminal charges can be brought only by the government  Law enforcement agencies have authority to seize evidence

14. 14 Comparing Criminal and Civil Laws CharacteristicsCriminal LawCivil Law ObjectiveTo protect society’s interests by defining offenses against the public To allow an injured private party to bring a lawsuit for the injury PurposeTo deter crime and punish criminals To deter injuries and compensate the injured party Wrongful actViolates a statuteCauses harm to an individual, group of people, or legal entity Who brings charges against an offender A local, state, or federal government body A private party—a person, company, or group of people (Continued)

15. 15 Criminal and Civil Laws (Cont.) CharacteristicsCriminal LawCivil Law Deals withCriminal violationsNoncriminal injuries Authority to search for and seize evidence More immediate; law agencies have power to seize information and issue subpoenas or search warrants Parties need to show proof that they are entitled to evidence Burden of proofBeyond a reasonable doubt Preponderance of the evidence Principal types of penalties or punishment Capital punishment, fines, or imprisonment Monetary damages paid to victims or some equitable relief

16. 16 In Practice: Distinction Between Criminal and Civil Cases Distinction between civil and criminal violation is not always clear In Werner v. Lewis case (Civil Court of N.Y. 1992)  Lewis inserted a time bomb (malicious computer program) into system (a crime)  Werner was awarded damages as in a civil suit

17. 17 Information Warfare and Cyberterrorism Information warfare is the extension of war into and through cyberspace Defenses against cyberterrorism  USA PATRIOT Act of 2002  FBI’s Computer Forensics Advisory Board

18. 18 Computer Forensics Skills An investigator’s success depends on three skill sets Value of recovered evidence depends on expertise in these areas

19. 19 Evidence Basics Evidence is proof of a fact about what did or did not happen Three types of evidence can be used to persuade someone:  Testimony of a witness  Physical evidence  Electronic evidence Both cybercrimes and traditional crimes can leave cybertrails of evidence

20. 20 In Practice: Forensics Saves a Life In 2004, Bobbie Jo Stinnett was murdered and her unborn baby “kidnapped” Police examined her computer and traced an IP address to Lisa Montgomery Montgomery had corresponded with Stinnett over the Internet

21. 21 Types of Evidence Artifact evidence— change in evidence that causes investigator to think the evidence relates to the crime Inculpatory evidence— evidence that supports a given theory Exculpatory evidence— evidence that contradicts a given theory Admissible evidence— evidence allowed to be presented at trial Inadmissible evidence— evidence that cannot be presented at trial Tainted evidence— evidence obtained from illegal search or seizure

22. 22 In Practice: Search Warrant for Admissible Evidence A search warrant is issued only if law enforcement provides sufficient proof that there is probable cause a crime has been committed The law officer must specify what premises, things, or persons will be searched Evidence discovered during the search can be seized

23. 23 Types of Evidence (Cont.) Circumstantial evidence—shows circumstances that logically lead to a conclusion of fact Hearsay evidence— secondhand evidence Material evidence— evidence relevant and significant to lawsuit Immaterial evidence— evidence that is not relevant or significant

24. 24 Rules of Evidence and Expert Testimony Federal Rules of Evidence (Fed. R. Evid.) determine admissibility of evidence According to Fed. R. Evid., electronic materials qualify as “originals” for court use An expert witness is a qualified specialist who testifies in court Expert testimony is an exception to the rule against giving opinions in court

25. 25 Electronic Evidence: Technology and Legal Issues Discovery requests for electronic information can lead to considerable labor Electronic evidence is volatile and may be easily changed Electronic evidence conversely is difficult to delete entirely E-mail evidence has become the most common type of e-evidence

26. 26 Importance of Digital Forensics Digital forensics investigations supply evidence for:  Criminal cases such as homicide, financial fraud, drug and embezzlement crimes, and child pornography  Civil cases such as fraud, divorce, discrimination, and harassment Digital forensics also used to prevent, detect, and respond to cyber attacks

27. 27 Digital Forensics Can Reveal... Theft of intellectual property, trade secrets, confidential data Defamatory or revealing statements in chat rooms, usenet groups, or IM Sending of harassing, hateful, or other objectionable e-mail Downloading of criminally pornographic material Downloading or installation of unlicensed software Online gambling, insider trading, solicitation, drug trafficking Files accessed, altered, or saved

28. 28 Digital Forensics Can Recover... Lost client records intentionally deleted by an employee Proof that an ex-employee stole company trade secrets for use at a competitor Proof of violations of noncompete agreements Proof that a supplier’s information security negligence caused costly mistakes Earlier drafts of sensitive documents or altered spreadsheets to prove intent in a fraud claim

29. 29 Fourth Amendment Rights The Fourth Amendment protects against unreasonable searches and seizures  Covers individuals and corporations Home Workplace Automobile  Law enforcement must show probable cause of a crime

30. 30 Discovery Process Pretrial right of each party to “discover” or learn about the opponent’s case Includes information that must be provided by each party if requested There are many methods of discovery

31. 31 Discovery Methods Interrogatories  Written answers made under oath to written questions Requests for admissions  Intended to ascertain the authenticity of a document or the truth of an assertion Requests for production  Involves the inspection of documents and property Depositions  Out-of-court testimony made under oath by the opposing party or other witnesses

32. 32 Rules Governing Discovery Federal Rules of Civil Procedure  1970 Amendment to Rule 34 addressed changing technology and communication Federal Rules of Discovery categorize electronic records as follows:  Computer-stored records (active data, replicated data, residual data, backup data and legacy data)  Computer-generated records (cache files, cookies, web logs and metadata)

33. 33 Electronic Discovery (E-Discovery) Discovery of e-evidence Landmark case involving e-discovery  Zubulake v. USB Warburg (2003)  “The more information there is to discover, the more expensive it is to discover all relevant information” Increased demand for e-discovery

34. 34 Categories of Stored Data Based on Zubulake vs. Warburg (2003), courts recognized five categories of stored data:  Active, online data  Near-line data  Offline storage/archives  Backup tapes  Erased, fragmented, or damaged data

35. 35 Increased Demand for E-Discovery Most business operations and transactions are done on computers and stored on digital devices Most common means of communication are electronic People are candid in their e-mail and instant messages E-evidence is very difficult to destroy

36. 36 Summary E-evidence plays an important role in crime reconstruction Crimes are not limited to cybercrimes; cybertrails are left by many traditional crimes Without evidence of an act or activity that violates a statute, there is no crime Rules must be followed to gather, search for, and seize evidence in order to protect individual rights

37. 37 Summary (Cont.) E-discovery refers to the discovery of electronic documents, data, e-mail, etc. E-discovery is more complex than traditional discovery of information Tools used to recover lost or destroyed data can also be used in e-discovery of evidence