In the last couple of days several deaths have been reported, including a wealthy retired man who had his Mercedes SLK coupe stolen after being shot dead, and two teenage thugs who tried to steal an off duty policeman's motorbike were shot dead by him in self defence.
La Matanza is probably the heart of Peronism in the province and indeed the mayor is the ultra K Veronica Magario who presides over a fuedal and corrupt area of some 2.2 million people who mainly live in squalor, with a 40% poverty rate.
Here's an article from La Nacion. To translate to English you'll need to open it in Chrome and hit translate to English. It's grim reading.