Simple Case mode assumes that there are two nonmixed samples (typically the evidentiary sample and the suspect) that should be compared. At the beginning Grape's main window looks as follows

If you want to change the default names "Evidentiary Sample" and "Suspect" to something else (for example, enter the real name of the suspect) click Setup Case button and you will be able to do so.

The loci you can use for your statistical evaluations can be selected from the Available Loci library that Grape loads at the start of the program from file loci.loc. Grape comes with a predefined set of Available Loci, but it is quite common that you may want to change loci in this library (for example, change alleles frequencies or add another locus). To do so just click Edit Loci button to change existing loci or Add New Locus button and you will be provided with a convenient graphical interface to complete the task.

Since probably only a part of all loci from the Available Loci library are actually used in calculations you need to select this part: click Select Loci button to do so.

Next step is to set genotypes of the suspect and the evidentiary sample. Grape has a nice tool for setting genotypes that allows user to set genotypes quickly and minimize the possibility of incorrect input. Besides manual genotype input Grape also supports importing of genotypes from the embedded databases that can contain hundreds of thousand of records. This automatic input reduces the routine human data entry, saves time and almost eliminates the possibility of an error. Both manual and automatic input is available through Set Genotypes dialog.

Grape supports calculations for structured population: use Choose Θ button to set the value of the coancestry coefficient.

Case Info button allows you to enter additional text information that helps organize your data properly. Three fields are available: case name, reference number and comments. You can use these fields in any manner you want.

At this stage the case is created and ready for evaluation. Grape's main window now looks like the following

To begin calculations click "Calculate" button. Calculation results will be displayed at the top of the window. The results include match probabilities and likelihood ratios calculated for each selected loci as well as total values over all loci (assuming statistical independence between loci). The resulting document for the example above is the following

This document can be printed or saved in a file. If this document is saved it can be opened again with Grape. Such file is saved in HTML format and can be viewed (exactly the same way as in Grape) with any Internet browser like Microsoft Internet Explorer. It can be rather convenient if, for example, you would like to send this document to somebody else who does not have Grape installed: even in this case that person can have exactly the same screen as Grape displays in its main window.

With thousands of cases processed saving resulting information in file format becomes not flexible enough for proper data organizing. Grape provides capability of saving cases into embedded databases that have advanced tools of quick searching and managing of large volumes of information. Additionally, Grape databases allow for effective data searches within its databases for matches that make it possible for instance to find serial rapes. To save a case into a database click Save to Database button.