Found at Rebelión (in Spanish): scroll down for the specific sources' links, all seemingly in English, many of them from The Brad Blog.
The story begins in 2003 in a Florida motel, where Raymond Lemme, Florida Attorney General's officer in charge of investigating the allegations of Republicans rigging the elections in that state in the year 2000 elections, was found dead with two cuts in his right arm. Police declared "suicide" but anyone with some knowledge of suicide techniques knows that it is virtually impossible to kill oneself that way (no matter what Holywood says: it is an attention-calling performance or a stupid failure, not any effective method of self-destruction). Anyhow, there was never any forsenic examination in spite of all the strange elements concurring (for example he had left that motel room the night before, not to mention his political relevance).
In 2008, Mike Connel, an important figure in the Bush' gang, especialized in informatics and very close to Karl Rove, died in a private airplane "accident" just minutes after taking off. This happened soon before he was going to witness in trial for the election rigging in Ohio in 2004, a state that decided GWB victory. He had already released information to the prosecutors, who considered him a key witness and asked for his institutional protection, which was declined.
He was also implicated in vote rigging in senatorial elections in Georgia.
Moral? Use the classical transparent ballot boxes: e-voting is a scam. .