Introduction to Time Series Graphs in Criminal Justice

1. Start the lesson with a question to the students using a scenario situation of a crime.

   1. Five years ago an interesting scenario occurred during a bank robbery in Jacksonville. The bank robbers parked the get away vehicle in front of the bank and all of the robbers went inside to perform a successful heist. However, when the robbers left the bank to drive away in their get away car that was left running and unattended, another unrelated criminal took a joy ride in the car. In other words, if you rob a bank and run out with the loot make sure that you do not leave the getaway car running so that another criminal can steal your get away car. What happens over time? Do the criminals get smarter and recruit a get away driver or do the police hire more officers to try to curtail crime? Does crime increase or decrease over time? Let’s look at criminal behavior and crime statistics over time using a time series graph.

      1. Educate students on what a time series graph is.

         1. How to construct a time series graph

            1. Let the x axis or the horizontal axis represent the time duration.

            2. Let the y axis or the vertical axis represent the number of crimes committed during the specific time duration.

         2. Use the table below to construct a time series graph of robbery in the United States from 1995 through 2000.

Crime in the United States, 1995-2000
Population by year:	Homicides	Rape	Robbery	Larceny/ Theft
1995-262,803,276	21,606	580,509	2,593,784	7,997,710
1996-265,228,572	19,645	535,594	2,506,400	7,904,685
1997-267,783,607	18,208	498,534	2,460,526	7,743,760
1998-270,248,003	16,974	447,186	2,332,735	7,376,311
1999-272,690,8134	15,522	409,371	2,100,739	6,955,520
2000-281,421,906	15,517	407,842	2,049,946	6,965,957

2. Criminal Justice Application Concepts

   1. Crime is measured in different ways. The most common way that we measure crime in the United States is by using the FBI statistics that are published annually in the Uniform Crime Reports (UCR).

      1. Includes 8 index crimes, both property and violent

      2. Includes raw numbers and rates

      3. Strengths and weaknesses of the UCR

      4. Does the real data coincide with what the media portrays?

      5. What are some of the factors that influence and alter crime from year to year?

         1. 1960’s crime problems and introduction of drug crimes

         2. Economic issues of the 1980’s and crime fluctuations

         3. Currently is crime up or down?

            1. Use of rates to compare different years and crimes

            2. Why rates are important

         4. Let’s look at some actual data of crime and see how it looks over time.

3. Mathematical Application Problems

   1. Plot a time series graph of the number of homicides committed from the years 1995-2000 using the UCR data above.

   2. Plot a time series graph of the number of rapes committed from the years 1995-2000 using the UCR data above.

   3. Plot a time series graph of the number larceny/theft committed from the years 1995-2000 using the UCR data above.

   4. Discuss the similarities and differences of time series trends among the different crimes (homicide, robbery, rape, and larceny/theft).

   5. Is crime really up or down over this 5 year period?

   6. What factors might contribute to the changes of crime?

   7. Would the results be different if we were using crime rates instead of the actual incidents of crime? Why or why not?