Bock said Brees died while staying at the home of a friend in Granby near Rocky Mountain National Park.
It took longer than three months for autopsy results to be released, but Bock said that's typical for cases involving toxicology tests.
The Austin American Statesman reported that three days before Brees died, the Texas attorney general's office subpoenaed her business records.
She had allegedly sent letters to some restaurants in Austin and Houston stating that they had lost their rights to use their names to a company she represented, Chicksports, but they could win the rights back by paying up to $25,000. She was also the president of Chicksports but that wasn't mentioned in the letter.
Relations between Drew Brees and his mother were strained at times and the quarterback asked her to stop using his picture in TV commercials touting her candidacy for a Texas appeals court seat in 2006.
Mina Brees said she had not anticipated upsetting her son and sent out replacement commercials omitting mention of him.
At the time, Drew Brees called his relationship with his mother "nonexistent," saying it crumbled six years earlier when he refused to hire her as his agent.
Austin attorney Marty Akins, the brother of Mina Brees, declined comment late Friday.