The Romans had no Police

I have stated repeatedly in 'Death in Londinium' and the forthcoming sequal 'Games in Londinium' that the Romans had no police force, and some historians have asked me to justify this statement. So: in about 100 AD when my books are set, in Rome itself there were three organisations who might have been a police force: The Praetorian Guard, the Urban Cohorts, and the Vigiles. But the Praetorians were a legion of elite solders, who defended Rome, and had the last word in civil, military and political matters. They certainly did not patrol the city with a cheery wave, nor chase thieves, nor help old ladies across the street.
The Urban Cohorts (four of them, with about five hundred men to the cohort) were closer to being policemen, though of the heavy-handed kind. Their job was riot control, and perhaps their mothers loved them, but nobody else did and you wouldn’t want to be on the street when they were.
Finally the Vigiles (seven cohorts) who patrolled at night, and might well have arrested drunks if they fell over them. But the Vigiles were really the Roman fire brigade. Their job was to find and put out fires, and that is what they mainly did.
What Rome did not have was a body of men whose primary duty was to prevent crime if they could, and investigate it if they could not: seeking evidence, pursuing criminals and then handing them over to a State prosecution service to be charged in court. In fact nobody could take that last step, because the Romans had no state prosecution service either.
All this suited the Romans because of the way their society worked. Thus a Roman Paterfamilias (head of the family) lived all his life in his city where he knew his neighbours and they knew him, and everyone knew everyone’s business thanks to gossiping slaves who knew absolutely everything that went on in the house. Then, within that house, Paterfamilias had absolute power to deal with any crime. He could beat, fine, imprison or even kill any member of his household.
How, then, did this affect some of the crimes that we fear most, starting with the worst fear of all: abuse of our children by paedophiles?
In a Roman city, if someone’s son had a sexual interest in children, then everyone knew because there was no privacy in a Roman house. I repeat that there was no privacy because the slaves would see everything and then gossip. So the son’s oddity would be common knowledge, and his Paterfamilias would warn him to behave or else, and if Paterfamilias himself was odd, then all his neighbours would know and he would never be allowed near their children.
Burglary in the night while you are asleep? In Roman law, men armed with military weapons could be seen as a rebels against the State (very dangerous! See below). So the burglar might have just a knife, which could be met by the house-folk with kitchen knives. But more important, a Roman family could be very large. Even a small household might be two parents, several children (some full-grown) plus numbers of slaves, while a large household would contain dozens of slaves. Thus burglary meant breaking into an armed and hostile community, and I doubt that any Roman criminal would even attempt anything so stupid.
Street crime? Muggers, pick-pockets and such? Romans relied on their neighbours against them since it was in everybody’s interest to defend one another. Also, Paterfamilias would always be attended by one or more slaves who were legally compelled to defend him.
So most petty crime was dealt with by Paterfamilias himself, or with the neighbours, as a private matter in which the State did not intervene. Big crime: legal, financial, commercial or political, was different. It was indeed a matter for the State, via the law courts. But Paterfamilias was expected to bring charges, produce evidence, summon witnesses, and even drag the accused to court.
Also dragged into court were the criminals Rome detested most: the noxii (scum) including rapists, kidnappers of children for ransom, and rebels against the state. They were damnatio ad bestias (condemned to the beasts) providing light entertainment in the arena before the gladiators came on.
That was the Roman defence against crime and it worked for hundreds of years. It wasn’t perfect but neither is London’s Met or the NYPD.