I'm asked regularly, "Did you create the SLED Test?" The tool has become a mainstay of STR's pro-life training, but it actually originated with a book by Stephen Schwarz, The Moral Question of Abortion in Chapter 1. (I've linked here to the online version of Schwarz's entire book, one of the best-kept secrets of the internet.)
Francis Beckwith shared the tool with a wider audience through his masterful Politically Correct Death.
Scott Klusendorf (Life Training Institute), Greg Koukl, and each of STR's speakers teach the tool in most of our presentations on abortion, and its included in the our pro-life training materials available in our online store, including Pro-Life 101 and Making Abortion Unthinkable.
Don't know what the SLED Test is? Check out my short description.