'Portrait of an Assassin' is a purposefully jumpy yet captivating tale of some of the life of Charles Guiteau, who assassinated President James Garfield (20th US president) in 1881.  Prima facie, James Jr.'s radio play seems an over-the-top rendition of the notorious figure, but after some research of my own, it seems Guiteau was as manic and bi-polar as portrayed.  In 1875, the future assassin's own family attempted to have him committed to an asylum.  During his federal trial Guiteau was wont to engage in such strange behavior as deriding his defense team, reciting lengthy prose, and soliciting members of the public gallery for legal opinion.  Getting back to the radio play, John Lithgow's performance is outstanding as usual and he remains one of my all time favorite Mystery Theater actors (his best performance is as the main character of a fantastic science fiction episode entitled 'Prisoner of the Machines').  The ubiquitous Robert Dryden is his excellent self (how many times has he portrayed someone's uncle in the series?) Elsewhere, I think it is Himan Brown who provides yet another jewel of a cameo in his portrayal of a White House official during Act Three. As a lover of Mystery Theater and a great appreciator of its father, I delight in discovering the occasional role where Brown's distinctive voice enjoins an episode and imagine his thrill in standing at the microphone while producing the show.  'Portrait of an assassin' is a quality episode, especially as it stimulates the desire for learning more about this fascinating period in our nation's history.  It earns 4 out of 5 stars. - JUROR #4