criminal psychology

What is criminal psyhcology?

• focuses on the psyhcological aspcts of criminals/ criminal behaviour / sociall contexts of crime
• deals with teh psychological aspects of criminal investigation such as eye witness testimonys

What is an eye witness testimony?

•  a reconstruction of witnessed events used in law courts as evidence
• however accuracy is varied becuse of many factors 

What did the DEVLIN REPORT 1976 report?

• out of 2000 line ups 45% resulted in a perp being picked out
• out of this 45% - 82% resulted in conviction
• out of 2000 cases 350 had an eye witness - 74% of these resulted in conviction 

so to sum up?

• eye witness testimonys are very importnat
• Jurors have great faith in them (PANROD AND CUTLER 1995)

(Because of this EYT is one of the most resaerched topics in criminal psychology)

Why is this dangerous?

• Innacurricies are very frequent
• EYT misindentifaction and innacurricies = leading cause for wrongful conviction in the US -more than any other causes combined (INNOCENCE PROJECT, 2005)

Give an example of EYT misindenditfication?

• JAMES CHARLES DE MENEZES 2005

What can effect EYT accuracy?

• biases in perception in and attention
• memory and expectations
• post event factors
• within event factors

BIASES IN PERCEPTION AND ATTENTION:

OWN ANCHOR EFFECTS - FLINN AND SHEPARED 1986

• study involved 588 particpipants
• found that their estimation of a targets height and weight differ depending on whether or not they themsleves are above or below average
• participants use their own physical charcteristics as a norm to base descriptions of others off
• aslso found that people have a tendancy to shy away from extreme judgements and regress towards the mean - e.g. underestimate height of tall poeple and over estimate height of short poeple
• "in regards to the criminals appearance, the most important determinant of this type of estimate is the witnesses own wieght and height" (MEISSNER, SPOROER, SCHOOLER 2007)

DISTANCE AND LIGHTING

• it is assumed that the majority of crimes  takes place at night (MEISSNER, SPORER,SCHOOLER 2007)
• our vision is greatly reuced in low illumination 
• distance and lighting can effect and influence facial perception and accuracy

YARMEY 1986 

• examined eye witness recall under different conditions
• day/ begining of twilight/ end of twilight/ night
• lighting had significant effcet an reall ability
• superior during the day

KOPPEN & LUCHUN 1997

• better illumination and a closer distance allows much greater and stronger descriptions

INATTENTIONAL BLINDNESS SIMONS AND LEVIN 1998)

• Observers lack a precise and complete visual represntation of their world ( SIMONS AND LEVIN 1998, P.64)
• We are paticularly unable to detect change 
• we tend to focus on more importnat visual information
• and do not get a full representation
• we may not even perceive certain objects

GORILLA STUDY 1999

• 288 participants
• video of basketball being passed
• told to count passes
• 44 seconds in a gorilla walked through the game - lasted 5 seconds
• people with counted correctly and did not see gorilla / saw gorilla and counted incorrectly/ did not do either
• only 42% of people saw the gorilla
• this was a replice of…