Discuss as:

Report: Florida mother was drunk when she shot and killed 4 kids, self

Tonya Thomas is seen in a 2002 booking mug provided by the Brevard County, Fla., Sheriff's Office. Authorities say Thomas, 33, shot and killed her four children before killing herself on May 15 in Port St. John, Fla.

A Florida woman who fatally shot her four children before killing herself in May was drunk at the time, according to autopsy reports.

Tonya Thomas had a blood-alcohol level of 0.16 percent  -- two times the legal limit, according to reports cited by floridatoday.com. That's the equivalent of approximately 10 drinks for a woman her height and weight, Bruce Goldberger, a professor and the director of toxicology in the Department of Pathology, Immunology and Laboratory Medicine at the University of Florida College of Medicine, told floridatoday.com.

Thomas, 33, of Port St. John, used a .38-caliber revolver to shoot Joel Johnson, 12, Jazzlyn Johnson, 13, Jaxs Johnson, 15, and Pebbles Johnson, 17, before killing herself at the family’s home early May 15, police said.  A total of 19 shots were fired and each child was struck multiple times.

Though Thomas was impaired by alcohol at the time, police still don’t know why she killed her children.

“We’re not going to know the answer to that question, because she’s deceased,” Brevard County Sheriff’s Lt. Tod Goodyear told floridatoday.com. “She’s the lone person responsible for the deaths.”

With the results of the autopsy in, investigators will now close the case.

Roberto Gonzalez / Getty Images

Brevard County crime scene workers conduct an investigation after Tonya Thomas shot her four children and then herself May 15, 2012 in Port St. John, Florida. The children ranged in ages 12 to 17 and the family had a history of domestic complaints.

More content from NBCNews.com:

Follow US news from NBCNews.com on Twitter and Facebook