Guy Turcotte murder trial: Final Crown witness cross-examined

Guy Turcotte's lawyers questioned a final Crownwitness at length on methanol and its effects during a technicalcross-examination Thursday.

Toxicologist MartinLalibertwas questioned much of the afternoonover testimony that often sounded like an advanced course on toxicchemicals and drugs.

The case was put on hold briefly by Quebec Superior Court JusticeAndr Vincent on Thursday to allow defence lawyer PierrePouparttimeto prepare a cross-examination.

The cross-examination of the final witness will now spill into Friday.

Laliberttestified Wednesday thatTurcottewould have only consumedwindshield washer fluid about an hour before his arrest and suggestedmethanol, a toxic ingredient found in washer fluid, has minimal impacton the brain.

Armed with scientific literature, the defence attempted to demonstratethat those health effects can vary greatly from person to person.

Turcottehas pleaded not guilty to two counts of first-degree murderin the stabbing deaths of his son, Olivier, 5, and his daughterAnne-Sophie, 3.

The ex-doctor has admitted to causing their deaths, but his lawyersargue the 43-year-old should be found not criminally responsible byway of mental disorder.

The accused testified he drankthe fluidon Feb. 20, 2009, to take hisown life and decided to also kill his two young children to spare themthe pain of finding his body the next day.