It was a week ago the workplace shooting at Valley Protein took place.
The preliminary toxicology report for Lawrence Jones showed negative for common street drugs except marijuana.
"It was proactive for cannabis. We can't tell from the report how much he took and how long ago," Fresno County Coroner, David Hadden said.
Hadden says while marijuana is a street drug, but in this case it's not one that would create a lot of toxic effect.
"We test for common street drugs, and we found none present other than marijuana and we do not feel it would effect behavior," said Hadden.
Dr. Hadden says the next step is testing for stronger toxic drugs in the system.
"It is normal to separate 2 tests. The street drugs cause the most deaths so you run those first," Hadden said
They're looking for drugs that have more psycho-stimulant effects like methamphetamine.
"Meth is extremely toxic and would explain behavioral abnormality," said Hadden.
