A lawyer of film director Peter Rodger says the family called police several weeks ago after being alarmed by YouTube videos posted by his son "regarding suicide and the killing of people".
The attorney said police had conducted an investigation and interviewed the man. Police said the man appeared to have trouble making friends but did not find a history of guns.
Police have not formally named the suspect, who died following the attack.
More top news
The text-to-register service allows mobile users to add their number to the Telephone Preference Service 'do not call' database.
A consumer report found that a number of once-a-day sunscreens decreased in protection by an average of 74% after six to eight hours.
It will be mainly dry across the UK, but parts of Wales and England may experience thundery showers.