Murder has no Guilt

A mass shooting. An amoral Romanian gangster. A Russian oligarch who claims to be an honest businessman, but isn't.
No one knows who was the target or why, but there are eight dead. The men seem the most likely, or could have it been one of the two women, the attractive Gillian Dickenson, or even the celebrity-obsessed Sal Maynard?
There's a gang war brewing, and if there are deaths, they don't care as long as it's not one of them. But to Detective Chief Inspector Isaac Cook, it's his area of London, and he needs to find out who killed the eight.
It's unpredictable, and initially, it had been the West Indian gangs that had held sway in the area. But then, a more vicious Romanian gangster had usurped them. And now he's being marginalised by the Russians.
And their leader is the head of the most vicious Russian mafia organisation, and he's got residency in England, as well as money and influence, the ear of those in power.