Watch: Three things you need to know about the mushroom murder trial

An Australian woman accused of poisoning relatives with beef Wellington laced with toxic mushrooms is being cross examined in a murder trial.

On Thursday, prosecutors claimed that photos on 50-year-old Erin Patterson's phone showed her using kitchen scales to measure a lethal dose of the death caps.

Ms Patterson's in-laws, Don and Gail Patterson, both 70, and Gail's sister Heather Wilkinson, 66, all fell ill and died days after the lunch.

Katy Watson, the BBC's Australia correspondent, looks at the three key things to know about the trial so far.