By creating your crime scenes using a program like the SmartDraw Legal Edition:

Getting Started: Using a SmartTemplate
The SmartDraw Legal Edition provides you with hundreds of SmartTemplates that help you get started no matter what your diagram need.
To create a crime scene diagram, you can start with a Blank Crime Scene SmartTemplate, a Crime Scene Area SmartTemplate, or modify one of the examples, simply by clicking on a preview in the Preview Area.
These templates are pre-configured for crime scenes with the appropriate SmartPanel already chosen for you.
Almost all crime scenes start out as some sort of a floor plan of a residential home or an office.

Occassionally, you may also need to use an outdoor scene such as a park or street.
Luckily, SmartDraw provides you with plenty of examples of both.
And since many crime scenes are truly unique to a case, you can easily create your own custom floor plan using the drawing tools provided in SmartDraw.
Click here to learn more about drawing floor plans.