Just a theory. This came to me after reading about a similar case about a year ago in Oregon. Medical marijuana is legal in Ontario. Ms. Gleave was obviously a greenthumb. It is possible that she qualified for a card for any number of reasons. Possibly she gave up golf due to arthritis. She was already a smoker and pot can also be ingested or inhaled through a vaporizer for those who don't like to smoke. In Ontario, one can get a card if they are terminally ill, have AIDS/HIV, Multiple Sclerosis, epilepsy, arthritis, or pain and/or symptoms of numerous other disorders. Not everyone who qualifies for a card and grows their own medicine wants their friends to know about it. In fact, most are quite secretive about it due to the very real danger of theft.
http://canadaonline.about.com/cs/marijuana/a/medmarijuana.htm
What if Ms. Gleave grew, or possibly "over-grew" for some reason. My guess is that her pot would be extremely high grade as she would tend it incredibly well. She, more than just about anyone would understand the science behind the best grows. Indoor grow operations have been known to run into the millions of dollars. I just read about a bust in Canada which netted $5.26 million CA ($5.3 million US). As in Oregon, the growers typically have cards but some over-grow to make extra money. There's a ready market for medical grade pot as it has a high THC and the various strains are said to resemble fine wines. The exotic strains can fetch very high prices.
http://www.citytv.com/toronto/cityn...26m-in-marijuana-plants-from-uxbridge-grow-op
If this grow operation existed (and please believe me when I say you'd be shocked as to who might be growing), word could have leaked out through an employee or friend. It could have been an innocent, off-hand, or even seemingly private comment. Someone even poking around her house while she was at coffee could have seen something.
Someone could have thought that Ms. Gleave would be an easy target and have staked out her house watching her routine. They might have known that she stepped outside at night to smoke and that the dogs seemed to be elsewhere in the house--possibly by just looking in a window. LE has mentioned that there could have been more than one assailant. One would think that she could be easily dispatched but she might have put up a heck of a fight. That sounds like her. But someone attempting a home invasion to steal a crop which is near or at harvest is a criminal and can be vicious.
Remember, LE stated that some of the "items" stolen had been found in a ground search. That's been reported in other invasion robberies of grows. There will be a trail of pot as the thieves harvest it and load it up as quickly as possible.
To be clear, I live in Southern Oregon, which has the highest number of medical marijuana cards, per capita, in our state. In all, over 38,000 people have the license to grow in Oregon and sadly, there has been some violence. We hardly go a week without another story in the news. I've been very very surprised to find that people I would have never expected to have a grow operation, do--especially in this economy.
Just a theory, that's all.