The Deadly Picnic - Deductive Reasoning

Objective: to utilize deductive reasoning to decide who committed the murder

Centerville police discover the body of a 36-year-old white male (later identified as Gaven Brooks) in an open field of daisies about five miles out of town. Mr. Brooks’s body was discovered at 10:02pm Friday night, October 11. He was found lying face up on a yellow, queen size sheet. According to autopsy reports, one fatal gunshot to the back of the head ended Mr. Brooks’s life. Scientists estimate that death occurred at about 7:45pm.

As investigators scanned the crime scene, they made the following observations:

Paper plates filled with partially eaten fried chicken, potato salad, and chocolate cake were located near Mr. Brooks’s body.

An open bottle of red wine and two partially filled glasses of wine were found next to the yellow sheet.

One of the wine glasses had a smudge of red lipstick on the rim.

A recently smoked cigarette butt was found near the sheet.

Footprints from the road to the field were those of a male, size 10, and a female, size 5. The only footprints from the field back to the road were those of a female, size 5.

Car tracks of the same wheel base and tread pattern as Mr. Brooks’s automobile were found at the road. The car was not found at the scene.

Later that evening Mr. Brooks’s car was found abandoned in an empty parking lot in downtown Centerville.

Investigators believe that a female friend of Mr. Brooks was responsible for his demise. After questioning family and friends, it was discovered that the deceased had frequent social outings with six women who lived in or near Centerville. The women’s names are Rita, Lauren, Gail, Janice, Elaine, and Peggy.

Who was responsible for the murder? What events surrounded this murder?


After reading the Background Information, record some important pieces of information in Data Table 1.

Read the special notes (below) that the police gathered during their investigation. Record this information in Data Table 2.

Special Notes:

Janice works full time as a cosmetologist.

Elaine and Gail are school teachers.

Peggy and Elaine live together in a two bedroom apartment in downtown Centerville.

Gail lives in a nearby town called Jordan.

Elaine and Janice are very petite women - they wear size 4 blue jeans.

Gail and Janice are non-smokers.

Janice works part-time as an aerobics instructor at a health club in Centerville. She teaches a 7:30pm step aerobics class each Friday night and has not missed a class in two years.

Peggy is deathly allergic to grapes.

Peggy doesn’t wear lipstick.

Gail attends the aerobics class that Janice teaches. She has not missed a Friday night class in nine months.

Lauren works at a chemical supply house.

Rita’s father owns a rifle range.

Lauren is allergic to all species of flowering plants.

Rita is a florist.

Rita doesn’t wear lipstick.

Janice and Elaine have never met.

Janice and Gail hate the color yellow.

Lauren played center for a semi-professional basketball team five years ago. She has red hair and is 6 feet, 1 inch tall.

Postlab Questions:

1) Who do you believe killed Mr. Brooks?


2) Cite key pieces of information that caused you to believe the other five women were innocent.








3) What information helped you identify the murderer?




4) Write a two paragraph story that describes what you believe happened on the night of the murder. Explain how the couple got to the murder site, why they went there, what happened while they were there, and how the murderer escaped. What do you believe was her motive?










Data Table 1:



Description of location where body was found








Approximate time and day of death







Weapon used to inflict fatal wound







Description of any footprints, tire prints, lip prints, etc.. around the crime scene
















Description of objects found at or around the crime scene








Any other pieces of evidence that may help solve this crime













Data Table 2:


Comments on size of women

Occupation and hobbies

City or place she lives

Medical information

Miscellaneous information