The jury in the Joanna Yeates murder trial are to begin a second day of deliberations.
Judge Mr Justice Field has urged the six men and six women trying her neighbour Vincent Tabak at Bristol Crown Court to reach a unanimous verdict.
The defendant, 33, denies murder but admits the manslaughter of the 25-year-old at her flat in Clifton, Bristol.
The judge said the jury needed to focus on what Tabak's intention was at the time the landscape architect died.
"Did he intend to kill her or cause her really serious harm?" he asked. "The fact that afterwards the defendant may have regretted what he had done does not amount to a defence.
"If having examined the evidence, and despite the defendant's denial, you are sure that when the defendant strangled Joanna Yeates he intended to kill her or cause her really serious bodily harm, your verdict will be guilty.
"If you are not sure of his intentions when he strangled Joanna Yeates your verdict should be not guilty."
The jurors "should not allow emotion" or sympathy towards Ms Yeates' family and boyfriend Greg Reardon to cloud their judgment when making their decision, Mr Justice Field said.
Landscape architect Miss Yeates was last alive on the evening of December 17 last year. She was reported missing two days later when her boyfriend returned to their ground floor flat in Canynge Road after a weekend away.
Police launched a massive hunt for the university graduate but her body was found by dog walkers on Christmas morning in a country lane in Failand, North Somerset - just three miles from her home. The net closed in on Tabak and he was arrested on January 20 when police matched his DNA to samples found on Miss Yeates's body and clothing.