The Canadian Press LAVAL, Que. — A Crown attorney told jurors today that Adele Sorella was the last person to be seen with her daughters before they were found dead in the family home.On the first day of his closing arguments, Simon Lapierre repeated the Crown’s theory that Sorella alone had the opportunity to kill Amanda, 9, and Sabrina, 8, on March 31, 2009.He said it was impossible that another person entered the family home and killed the girls, noting that there was no evidence of a break-in or struggle and nothing had been broken. The girls’ bodies showed no signs of violence, and the cause of death was never determined.Lapierre said there is no reason to think the deaths were accidental. He reminded jurors of a first responder’s testimony that the girls were found lying side by side in their playroom, as if they had been laid there.The prosecutor also told the jury that the Crown is not required to establish a motive for the crime.Last week, Pierre Poupart, one of Ms. Sorella’s lawyers, spent four days going over the reasons his client should not be found guilty. Her trial on two charges of first-degree murder began in November.