There was "no indication" that anyone left the home of children's author Helen Bailey during the hours her alleged killer claims she ran away, a court has heard.
Analysis of the alarm system in her house in Royston, Hertfordshire, was said to show "no usage to correspond with someone going out" on the day the she vanished last April.
Her fiancé, Ian Stewart, told police he returned home to find it empty that day, with a note claiming she needed "space", the trial previously heard.
A jury at St Albans Crown Court was told that previous patterns suggested the alarm was activated "whenever the house is left empty", but it was possible Ms Bailey had left without doing so.
Helen Bailey was reported missing in April 2016.
Helen Bailey was reported missing in April 2016.
Stewart, 56, is accused of killing his bride-to-be after secretly sedating her in a long-planned plot to acquire her fortune.
That morning, April 11 2016, the alarm was said to have been disarmed shortly after 8am, when the defendant's son, Jamie, went to work.
It was only reactivated in the evening, around the time Stewart left to watch a game of bowls, with a key fob which appeared to be his, the court heard.
"On April 11 there was no real usage during the day; there was early-morning usage and some usage in early evening - there was no usage to correspond with someone going out.
"Whenever there was movement throughout the day on previous days the alarm was going on and off."
Detective Constable Lee Stewart, Hertfordshire Police
Prosecutor Stuart Trimmer asked: "It gives no indication if anyone went out,to the tip, or the doctor's?"
"That's correct," DC Stewart replied.
Simon Russell Flint, defending, asked the detective: "The pattern you found was that whenever somebody goes out it was activated - whenever the house is left empty?"
DC Stewart said: "That is the indication."
"You wouldn't activate it, set the alarm if you were going out but leaving someone inside the house?" Mr Russell Flint asked.
The witness responded: "There is no indication of that at all."
http://www.itv.com/news/anglia/2017...-show-someone-leaving-on-day-author-vanished/