Convicted sex offender Martin Tremblay has pleaded not guilty to a half-dozen charges stemming from the overdose deaths of two Metro Vancouver teenagers.

Tremblay, a man in his mid-40s, entered his plea Monday in B.C. Supreme Court, where he faces two counts each of criminal negligence causing death, obstruction of justice and failure to provide necessities.

Crown claims Tremblay had 16-year-old Kayla LaLonde and 17-year-old Martha Jackson Hernandez over to his Richmond home the night of March 2, 2010, and supplied them with methadone and alcohol.

He allegedly left the girls passed out there for hours before returning to find LaLonde in medical distress.

Instead of calling 911, Trembley contacted a friend to help him drive the unconscious girl to Burnaby and dump her there, the court heard.

LaLonde went into cardiac arrest at around 12:40 a.m. in the 4000-block of Rumble Street. Despite the efforts of two Good Samaritans and paramedics, she did not survive.

The girl’s family and friends were in court Monday, including LaLonde’s mother who was too upset to speak with reporters.

“Her emotions are all messed. Just seeing [Tremblay’s] face, she just wants to lose it. She’s got to hold her composure, she doesn’t know what to say,” said Grant, a family member of the deceased. “She’s like shell-shocked right now.”

The Crown alleges that when Tremblay returned home again, he failed to check on Hernandez and left a third time to take another girl to Tim Hortons.

An older woman in the house called 911 for Hernandez about seven hours later, the court heard, but the teenager was already dead.

As police investigated the girls deaths, Tremblay is accused of trying to convince witnesses to cover up what happened the night at his home.

Prosecutors say their evidence includes pictures and texts from the victims’ cell phones, and a video that was found inside Tremblay’s house.

Later this week, the court is expecting testimony from Hernandez’s stepmother, who approached Tremblay in the days after her stepdaughter’s death.

With a report from CTV British Columbia’s Lisa Rossington