(CNN) -- A California woman who police say planted two bottles of tainted orange juice at a San Jose Starbucks has been charged with attempted murder, a police spokesman said Tuesday.
Ramineh Behbehanian, 50, is accused of adding rubbing alcohol to the contents of the bottles and then placing them into a refrigerated display case, Police Sgt. Jason Dwyer told reporters.
"According to our San Jose firefighters that were on scene and the fire captain there -- they really are the experts there -- it was a lethal dose," he said.
Behbehanian was arrested Monday after a customer spotted her allegedly pulling out two bottles of orange juice from a bag and putting them in the display case, he said.
The customer reported it to employees, who in turn followed Behbehanian out of the store, according to police. The employees got a license plate number, and investigators later traced the plate to Behbehanian's residence, Dwyer told reporters.
The employees also immediately pulled the bottles of orange juice from the display case.
Dwyer would not comment on the evidence in the case nor a possible motive, saying authorities were "still very much in investigative mode."
He did say the bottles were opened rather than injected by a syringe.
Starbucks did not immediately respond to a CNN request for comment.
CNN's Janet DiGiacomo contributed to this report.