The Sisters in Crime - Central Virginia chapter hosted Dr. Evan Nelson, who spoke on "The Murderous Mind." Dr. Nelson is a forensic psychologist, and he specializes in criminal evaluations. He has served as an expert witness in a variety of cases. His discussion was geared for those who write mysteries and thrillers.

Here are some of the things I learned from his presentation and the question/answer session...

1. Forensic psychologists don't investigate crime scenes (like they do on TV).

2. People in this profession make a recommendation about whether the accused is competent to stand trial and assist in his/her defense.

3. Many of the accused don't plead insanity because they don't want to be sentenced to a mental facility.

4. Fifty percent of murder/victims know each other and 25% of those have some sort of direct relationship or involvement.

5. Love and hate are opposites, but each cause impassioned responses (revenge, anger, retribution, and control).

6. If you are writing about domestic murders (ones where the murder/victim have some sort of relationship), you need to make sure that you include the background history. The murder may have happened in the heat of the moment, but there is usually a history of issues.

7. Many convicted of murders that occurred in the heat of the moment have a history of using violence to solve problems and making impulsive decisions.

8. Eighty percent of murders have some sort of alcohol and drug involvement.

9. Fifty percent of the victims autopsied have alcohol present in their systems.

10. Cocaine and alcohol together make the high more potent and longer-lasting. Characters who abuse both are often violent and will commit crimes in order to maintain their high.

11. Marijuana causes paranoia, and opiates cause withdrawal and anxiety.

12. Murders for hire aren't always high-dollar schemes. It depends on the murderer's background. Many murders for hire have been for relatively small amounts of money.

13. For multiple offender violence, "group think" is involved. The members like to maintain harmony, and they do extreme things that individually they probably wouldn't do. Group dynamics and the need for conformity play a large role in affecting the group's behavior.

14. Many of those who kill family members or friends suffer from post-traumatic stress syndrome after the murder.

15. Communicating through electronic devices often causes users to lack censorship/filtering and empathy that they may otherwise have in face-to-face conversations.