Interesting information! Thanks!
But I think it was Virgil Earp who was wounded in an assasination attempt, not James. Also Morgan Earp was killed in another shooting. But James, who was badly wounded and lost the use of his arm at Fredericktown (while serving with the 17th Illinois I think), never seems to have participated in any of the law-making/law-breaking affairs of the other Earps, other than to have followed them from place to place working as a hotel or bar operator.