In itinere - During the journey (Legal term - Something that happens during the fact)
In ius vocatio - Call for justice (Legal term)
In limine litis - At the beginning of the process Legal term)
In loco parentis - In lieu of parents (Legal Term - often used in Family Court to assign parental responsibilities often on non-biological parental substitutes/parties - Thank you: crj)
In mediu virtuas - The truth is in the middle (Legal term - neither party is right)
In solidum - Solid, total (Legal term)
In solutum - In soluble, in payment (Legal term )
In vigilando - In vigilance (Legal term - Obligation to supervise the work of others)
In voce - In voice (Legal term - verbal, not written)
Inde datae leges, ne fortior omnia posset - The laws were made lest the stronger should be all powerful (Legal term - Ovid, Fasti III, 279)
Instrumentum vocale - A tool that speaks (Legal term - Refers to slave who did not have an rights)
Inter partes - Among the parties involved (Legal term)
Interposita persona - An intermediary (Legal term - Sometimes refers to a front man used to disguise an unlawful transaction )
Interpretatio largo sensu - Interpreted in general (Legal term - as opposed to strictu sensu)
Interpretatio stricto sensu - Interpreted strictly (Legal term - as opposed to largo sensu)
Intuitu pecuniae - In response to money (Legal term)
Intuitu personae - In consideration of the person (Legal term)
Inveterata consuetudo et opinio iuris seu necessitatis - Inveterate habit and the opinion or necessity of law (Legal term - Usually - Unwritten Laws and behavior that follows people constantly: conviction of those people that such behavior is mandatory)
Invito domino - Against the will of the owner (Legal term)
Invitus nemo rem cogitur defendere - Nobody will be forced to defend the object (Legal term - Domitius Ulpianus - Digest 50,17,156 - )
Ipse dixit - He himself said it (Legal and philosophical term - Fallacy in which the only proof, are the words of who makes the assertion)
Ipso facto - By that very fact (Legal term - Fact that has a Judicial consequence)
Ipso iure - By law (Legal term - As opposed to facts Ipso facto)