Please keep in mind that this blog often has comments and statements directly from the women on death row. Statements of grief, statements of innocence, statements of regret and sorrow. If bearing audience to these women's feelings, my opinions or those of commenters offends you please do not read on.
Psychology and Psychiatry in Courts and Corrections: Controversy and Change (Wiley series of personality processes)

Psychologists have had a changing and ever more important yet controversial role in corrections and criminal justice throughout history. Each department of criminal justice calls for a distinctly different need in psychology. In turn, psychologists can perform greatly different duties in each sector of criminal justice.
Law Enforcement
Law enforcement agents can be put in dangerous situations. Their lives are put in danger every day. When dangerous and violent occurrences happen to police officers it is no different than when it happens to civilians. It can be traumatic and life changing. Psychologists are used in law enforcement to help officers deal with traumatic situations.
When an officer must pull his weapon and fire upon another human being that alone can be stressful. However, if that person should die at the hands of the officer it can be very traumatic. Killing another person, even or especially in the line of work can cause mental damage to the officer. Some psychologists specialize in traumatic stress and are placed in law enforcement to provide therapy to officers who have been part of or witnesses traumatic stress. Psychologists can also help victims and witnesses of crimes as part of their job in law enforcement. (http://www.aaets.org/article87.htm)
Corrections
Prisons and jails are not easy places to live. Violence and dangerous situations are always possible. Not all people in the corrections system are violent criminals. Some prisoners have trouble adjusting to life in prison and need counseling provided by psychologist to adjust and attempt to find a way to cope during their prison stay. Psychologists are often called in to provide therapy specifically to women because of the special needs they face. According to J.M. Pollock in Counseling women in Prison, sociological issues in prison effect women more dramatically than men. Being a wife and/or a mother from jail causes specific problems unique to women. A psychologist in a womens prison can provide these specific therapies to women who are having trouble coping.
Court
psychologists are important in a court room for both children and adults. The provide counseling to witnesses in criminal cases as well as therapeutic sessions to those charged with crimes and facing sentencing.
Psychologists are important when children are brought in as witnesses. Children have a far different mental capacity than adults and a psychologist must be on hand to help determine if the child's testimony can be trusted and will be useful. Also, when a juvenile is accused of a especially violent crime and in danger of being waived through court as an adult, a psychologist must examine the youth and determine if it is appropriate to move the juvenile into adult court.
The most important function of a psychologist in court may be to determine if the accused is mentally stable to stand trial. This is a major part of our justice system and the very basis of our court system in America. Without the preliminary examination of a psychologist saying the accused is of sound mind many cases would be thrown out and violent criminals set free. http://www.psychologyinfo.com/forensic/criminal_court.html
According to an article on Uplink.com, there is no recent, adequate information on the ethical issues in correctional psychology. http://www.uplink.com.au/lawlibrary/Documents/Docs/Doc93.html
However, the ethical standards for psychologists in the field of criminal justice are different from those in the civilian world. The very fact that these clients are criminals or involved In a criminal venture calls upon a specific ethical structure within the treatment itself.






Resources

http://www.aaets.org/article87.htm

Pollock, JM. Counselling women in Prison.Sage Publications, Inc. 1998

http://www.psychologyinfo.com/forensic/criminal_court.html

http://www.uplink.com.au/lawlibrary/Documents/Docs/Doc93.html