One of Sydney's most notorious crime bosses is dead. Gunned down in an execution style murder on a quiet street in Greenacre. Mahmoud “Brownie” Ahmad had a bounty of $1 million on his head. Police say what unfolded was only a matter of time. Brownie gunned down walking to his car. The 39-year-old was visiting an associate, but waiting for him was an assassin. Minutes later a BMW was burnt out at Belmore and a Porsche torched in Strathfield. Both are suspected getaway cars. Brownie was the brothe