causa prope perorata ipse arripuit M'. Aquilium constituitque in conspectu omnium tunicamque eius a pectore abscidit, ut cicatrices populus Romanus iudicesque aspicerent adverso corpore exceptas; simul et de illo vulnere quod ille in capite ab hostium duce acceperat multa dixit, eoque adduxit eos qui erant iudicaturi vehementer ut vererentur ne, quem virum fortuna ex hostium telis eripuisset, cum sibi ipse non pepercisset, hic non ad populi Romani laudem sed ad iudicum crudelitatem videretur esse servatus.
With the case almost concluded himself grabbed hold of Manius Aquilius and stood him up in the sight of everyone and tore the tunic from his breast, so that the Roman people and the judges could see the scars received on the front of his body; at the same time he said many things about that wound which he had received on his head from the leader of the enemies, and in this way persuaded those who were meant to judge the case to fear very much that the man whom fortune had snatched from the weapons of the enemies, when he had not spared his very person, that this man would seem to have been preserved not for the praise of the Roman people, but for the cruelty of the judges.
(Cicero, In Verrem V.3)
It's a dramatic, sensationalistic approach and Cicero here seems to regard it with cynicism- it was just a convenient trick to get Aquilius acquitted of his obvious guilt (something that Cicero himself would never stoop to doing, of course). But elsewhere Cicero describes the same event with more sympathy. In his De Oratore, he writes from the point of view of Antonius, giving him a chance to explain his actions:
Saepe enim audivi poetam bonum neminem sine inflammatione animorum exsistere posse et sine quodam adflatu quasi furoris. Qua re nolite existimare me ipsum, cum mihi M'. Aquilius in civitate retinendus esset, quae in illa causa peroranda fecerim, sine magno dolore fecisse. quem enim ego consulem fuisse, imperatorem ornatum a senatu, ovantem in Capitolium ascendisse meminissem, hunc cum adflictum, debilitatum, maerentem, in summum discrimen adductum viderem, non prius sum conatus misericordiam aliis commovere quam misericordia sum ipse captus, cum excitavi maestum ac sordidatum senem et cum ista feci, quae tu, Crasse, laudas, non arte, sed motu magno animi ac dolore, ut discinderem tunicam, ut cicatrices ostenderem.
For I have often heard that no man can be a good poet without a burning heart or without some kind of insane inspiration. And so do not suppose that I myself, when I had to defend Manius Aquilius against the State, did the things I did in closing that case, without great emotion. For I remembered that he had been consul, a general decorated by the Senate, that he had climbed the Capitol in triumph, when I saw him him humbled, crippled, sorrowing, his fortunes completely reversed, I was myself overcome by compassion before I tried to excite that same compassion in others, when I called forth that unhappy old man, filthy as he was, and when I did those things which you praise, Crassus, not as a trick, but affected by great pain in my heart- that is I tore open his tunic and exposed his scars.
(Cicero, De Oratore 194-5)