Sgt. Jim Edwards holds a bottle which contained methadone consumed by Summer Hope, who later died. (Darren Makowichuk, Sun Media)

CALGARY -- Three years after Summer Hope died, police are looking for the toddler's mother so justice is no longer denied for the little girl who drank a deadly dose of methadone.

Both her father, Jonathan Hope and mother Lisa Hope -- also known as Lisa Guerin -- are charged with manslaughter, criminal negligence causing death and failure to provide the necessaries after the deadly April 2006 overdose.

In January, she was a no-show at a preliminary hearing.

Now police are worried she might not appear at a trial set for September and have issued a warrant in a bid to find her.

"If she is not apprehended and held in custody, it may not proceed to trial," said Sgt. Jim Edwards, one of the original investigators.

"We want this trial held once and for all."

Not long after she was originally charged, Lisa vanished and was later arrested near Medicine Hat.

At some point over the years, while in custody, she gave birth to another child.

Police believe Summer's dad, a recovering drug addict, smuggled home methadone hydrochloride from a methadone program clinic where he was being treated.

Allegedly, Summer innocently drank the bitter opiate, likely mixed with juice, from a coffee cup left on top of a TV about 5:30 p.m. on a Saturday.

A lethal dose of the drug typically affects the central nervous system, causing someone's brain to shut down and breathing to stop.

Summer may have simply felt sleepy, slipping into a deadly coma.

But it went from an accident to a crime when, as police allege, neither of her parents took action.

"Both were aware and neither did anything to get her medical help," Edwards said.

The next day, Summer was unresponsive and Jonathan -- now home alone with his daughter -- claimed he did CPR for several hours, even ripping cords out of a clock radio to try to jump-start the toddler's heart.

Paramedics arrived about 2 p.m. but Summer was dead -- the child found lifeless and naked on a Winnie the Pooh blanket in the basement suite of a southwest fourplex.

Initially, police thought she died of natural causes, passed away in her sleep, perhaps a victim of sudden infant death syndrome.

Months later, toxicology testing showed Summer died of methadone toxicity.

Other than that, the 23-lb. child with red hair and just two front teeth was healthy.

Not long after, Summer's parents were charged.

"They neglected their daughter knowing full well she could die," Edwards said.

Lisa's friend, who overheard the toddler's parents arguing about who would get her help, is now a key witness in the case.

NADIA.MOHARIB@SUNMEDIA.CA