Simon Greenleaf (1783-1853) was a Jewish believer in Jesus and law professor at Harvard university. He wrote a book on apologetics using legal methods. This book is titled, “An Examination of the Testimony of the Four Evangelists.” It is available free to read online, download as a Kindle, PDF, or other formats at Project Gutenberg.
This book is broken into several sections. Here are three important ones.
First, at the beginning there is a section where he uses legal rules of evidence. He applies these principles to examining the gospels. He uses the ancient document rules. Also, he applies five rules of evidence to examining the gospels. These are first, Honesty, the general and specific honesty of the witnesses)p. Second, Ability is the ability for the witnesses to see, understand, and remember what happened. Third is the Number, Independence, and Consistency of the witnesses. Four is Experience, agreement of the testimony with general experience. Fifth, finally is Circumstances, the agreement of the testimony with specific evidence. You can read the short and very insightful use of legal apologetics Here.
Second, he has a large harmony of the Gospels. Here he uses his expertise to harmonize the different Gospel accounts. You can read it starting Here.
Third, he has a section focus just on the resurrection accounts. This is always important and especially timely for Easter. Read this short section Here.
Other Free Resources
Simon Greenleaf has influenced many Christian apologists including Wilbur M. Smith, John Warwick Montgomery, Josh McDowell, and Ross Clifford. His book is a significant work in a long history of Christian lawyers using the rules of evidence to defend the Bible and the resurrection of Jesus.
You can read more about his life on Wikipedia.
Here is a short review of his book at Historical Apologetics.
Here is an essay in a theological journal with over 90 people who have use the legal approach to apologetics Juridical Apologists 1600-2000 AD: A Bio-Bibliographical Essay.