"This confirms it. Aulus Cosconius was stabbed through the heart with a stylus uncleaned by its owner since its last use. A bit of wax still adhered to its tip and was left on the wound."
Quintus Cosconius snorted. "What of it? Nearly every literate man in Rome carries a stylus!"
"Actually, I didn't really forget my own stylus today." I took it out. "You see, the common styli are round or quadrangular. Mine, for instance, is slightly oval in cross-section." Cicero and his friends drew out their own implements and showed them. All were as I had described. Cicero's was made of ivory, with a silver scraper.
"Yet Asklepiodes's examination indicated that the weapon used to kill Aulus Cosconius was triangular. You will note that young Quintus's implement is of that geometrical form, which is most rare among styli." I handed it to Cicero.
Then I shook out the tunic the dead man had been wearing. "Note the three parallel streaks of blood. That is where he wiped off the sides of the stylus."
"A coward's weapon," snorted one of Cicero's companions.
"But young Cosconius here is standing for office," I pointed out. "He couldn't afford to be caught bearing arms within the pomerium. But most Romans pack a stylus around. It isn't much of a weapon, but no one is going to survive having one thrust through his heart."
"Why should I do such a thing?" Cosconius demanded. You could smell the fear coming off him.
"Yesterday," I said, "you told me you didn't know what use your father intended for that town house. Here is the deed from the Archive." I took the diptych from a fold of my toga and opened it. "And here he states plainly that it is 'to serve as a residence for his only surviving son, Lucius.' He didn't bother showing you this deed or getting your seal on it because he was a very old-fashioned man, and by the ancient law of patria potestas you were a minor and could not legally own property while your father was alive. He took you to show you your new digs, and that is where you argued and you killed him."
Everyone glared at Cosconius, but by this time he had gained enough wisdom to keep his mouth shut.
"Killed the old man for his inheritance, did he?" Cicero said grimly.
I shook my head. "No, nobody gets killed over money these days. It's always politics. Aulus Cosconius was generous enough with his wealth, else why give his son a whole town house to himself? But he supported Crassus and Quintus here is Pompey's man. Aulus wouldn't stick his neck out for Crassus, but he could keep Pompey from getting another tame Tribune without risk, or so he thought."
I addressed Cosconius directly. "Sometime during the tour of that townhouse he told you that he forbade you to stand for Tribune. As paterfamilias it was his legal right to do so. Or perhaps he had told you before, and you waited until you were together in a lonely spot to kill him. The law admits of no distinction in such a case."
Cosconius started to get hold of himself, but Cicero deflated him instantly. "I shall prosecute personally, unless you wish to, Decius Caecilius."
"I shall be far too busy for the balance of this year."
Cosconius knew then he was a dead man. Cicero was the greatest prosecutor in the history of Roman jurisprudence, which was precisely why I had asked him there in the first place. He took few cases in those days, but a parricide in a senatorial family would be the splashiest trial of the year.
I summoned the owner of the school. "Statilius, lend me a few of your boys to escort this man to the basilica. I don't want him jumping into the river too soon."
Cosconius came out of his stupor. "Gladiators? You can't let scum like that lay hands on a free man!"
"You'll have worse company soon," Cicero promised him. Then, to me: "Aedile, do your duty." I nodded to my borrowed lictor. He walked up behind Quintus Cosconius and clapped a hand on his shoulder, intoning the old formula: "Come with me to the Praetor."
That's the good part about being Aedile: You get to arrest people.
These were the events of two days in the year 703 of the city of Rome, the consulship of Marcus Valerius Messalla Rufus and Cnaeus Domitius Calvinus.