is the process of discovering, collecting, preparing, identifying and presenting evidence to determine what happened and who is responsible.
What is criminal investigation?
Determine whether a crime has been committed. Legally obtain information and evidence to identify the responsible person. Arrest the suspect. Recover stolen property. Present the best possible case to the prosecutor.
What are the major goals of criminal investigation?
Provide emergency assistance. Secure the crime scene. Photograph, videotape and sketch. Take notes and write reports. Search for, obtain and process physical evidence. Obtain information from witnesses and suspects. Identify suspects. Conduct raids, surveillance, stakeouts and undercover assignments. Testify in court.
What basic functions do investigators perform?
Obtain and retain information; apply technical knowledge; and remain open-minded, objective and logical.
What do effective investigators do?
They are emotionally well balanced, detached, inquisitive, suspecting, discerning, self-disciplined and persevering. They are physically fit and have good vision and hearing.
What characteristics are important in investigators?
Patrol officer assigned to the area where a crime has occurred.
Who usually arrives at a crime scene first?
Any suspect should be detained, questioned and then released or arrested, depending on circumstances. If a suspect has recently left the scene, officers obtain descriptions of the suspect, any vehicle, direction of travel and any items taken. The information is dispatched to headquarters immediately.
What do you do if a suspect is still at a crime scene? Has recently fled the scene?
All necessary measures to secure the crime scene must be taken--including locking, roping, barricading and guarding--until the preliminary investigation is completed.
How are the crime scene and evidence protected and for how long?
Questioning the victims, witnesses and suspects. Conducting a neighborhood canvass. Measuring, photographing, videotaping and sketching the scene. Searching for evidence. Identifying, collecting, examining and processing physical evidence. Recording all statements and observations in notes.
What responsibilities are included in the preliminary investigation?
Spontaneous statements made at the time of a crime concerning and closely related to actions involved in the crime. They are often considered more truthful than later, planned responses.
What is the meaning and importance of res gestae statements?
Know the elements of each major offense and the evidence that supports them and ascertaining whether they are present. Officers also try to determine when the event occurred.
How do you determine whether a crime has been committed?
Police personnel. It must be a cooperative, coordinated departmental effort.
Who is responsible for solving crimes?
Using a community policing orientation, investigators interrelate with uniformed patrol officers, dispatchers, the prosecutor's staff, the defense counsel, supervisors, physicians, the coroner or medical examiner, laboratories and citizens, including witnesses and victims.
With whom do investigators must relate?
Effective policies and procedures clearly communicated to all. Thorough and continuous training. Proper supervision and discipline. Accurate, thorough police reports.
How do you avoid a civil lawsuit?
person's risk of being sued. Any person acting under the authority of law who violates another person's constitutional rights can be sued.
philosophy that the police must work with the community through partnerships and problem solving to address problems of crime and disorder; a belief that by working together, the police and the community can accomplish what neither can accomplish alone.
act or omission forbidden by law and punishable bu a fine. imprisonment or even death. Crimes and their penalties are established and defined by state and federal statutes and local ordinances.
focuses on the location of crimes--the hot spots where most crimes occur--rather than on the criminal.
seeking all facts associated with a crime to determine the truth: what happened and who is responsible.
a person who searches for, collects and preserves physical evidence in the investigation of crime and suspected criminals. Also called a crime scene technician, examiner or investigator.
branch of forensic science involved with the recording, identification and interpretation of the minutiae (minute details) of physical evidence.
skilled in interacting across gender, ethnic, generational, social and political group lines.
process that uses powerful analytic tools to quickly and thoroughly explore mountains of data to discover new patterns or confirm suspected patterns or trends.
a logical process in which a conclusion follows from specific facts; a reconstructive process based on specific pieces of evidence to establish proof that a suspect is guilty of an offense.
conditions that must exist and be proven to exist for an act to be called a specific kind of crime
elements of the crime
physical evidence favorable to the accused, that would clear the accused of the blame; for example, having a blood type different from that found at a homicide.
major crime such as homicide, aggravated assault or robbery. Usually carries a penalty of imprisonment in a state penitentiary or death.
application of the physical sciences and their technology to examining physical evidence of crimes; includes the branch of criminalistics.
a "sudden knowing" wihtout any conscious reasoning or apparent logic. Based on knowledge and experience or what is commonly called street sencse. An intangible urge; a "gut feeling" developed by experience.
to observe or study closely; to inquire into something systematically in a search for truthful information.
basic forensic theory that objects that come in contact with each other always transfer material, however minute, to each other.
Locard's principle of exchange
minor crime such as shoplifting or pilferage; less serious than a felony. Usually carries a fine or a short sentence in a county or municipal jail.
act of the legislative body of a municipality or county relating to all the rules governing the municipality or county, including misdemeanor crimes.
spontaneous statements made at the time a crime is committed and closely related to actions involved in the crime. Considered more truthful than later, planned responses.
res gestae statement
Dr. Karl Landsteiner discovered the different human blood types and calssified them into the A, B, AB and O groups.
Dr. Edmond locard, a French criminologist, set forth his "exchange principle" stating that a criminal always removes something from a crime scene or leaves incriminating evidence behind.
Alec Jeffreys discovered the parts of the DNA structure that were unique in each person, making positive identification possible.