Sydney's terror attack is raising questions about intelligence shortcomings and where security systems could be beefed up.  

A 50-year-old man and his 24-year-old son allegedly shot dozens of people celebrating the Jewish holiday Hanukkah at Bondi on Sunday evening. 

The younger man had been investigated by the country's security agency before and wasn't considered a threat. 

A senior lecturer of terrorism and radicalisation told Heather du Plessis-Allan that intelligence services are probably watching dozens of people, forcing them to make decisions as to who is likely to be the most relevant threat at that time. 

Australian National University’s Dr Michael Zekulin says the alleged shooter didn’t meet the criteria in this case, which is something that’s been seen time and time again, in other countries as well.  

LISTEN ABOVE