The person was "shooting like insane", Mr Zambrano said, speaking in Spanish. The mother told her to take care of her father and the dogs.
Several people were shot on Thursday in Perryman, Maryland, and residents were asked to avoid the area, according to authorities.
Authorities say a call about shots fired came in from center at 9:06 a.m. Thursday, and deputies and other officers were on the scene in just over five minutes.
"The distribution centre is where products are received and processed for delivery", Rite Aid spokeswoman Susan Henderson said.
Victims have been transported to trauma centers in Baltimore and across the state border to DE, local CBS affiliate WJZ reported.
As of now, Gahler said that authorities are not revealing the identities of the victims, as their families are still being notified.
Carre said the man told him the shooter "just came in in a bad mood this morning".
An unidentified assailant opened fire Thursday at a warehouse complex north of the U.S. city of Baltimore in Maryland, killing and wounding multiple people, authorities said. Police said that she was apprehended in "critical condition".
Gahler said there are multiple injuries and multiple fatalities.
Citing a law enforcement official who spoke on the condition of anonymity, The Associated Press reported that three people were killed in the shooting. The suspect then opened fire with the handgun on people outside the facility before heading inside and open fire on people in there, according to officials.
The Hartford County Sheriff's Office said that it responded to the shooting at 9:09 a.m.
Mass shootings are common in the United States but the vast majority involve men and the Aberdeen incident is a rare mass shooting carried out by a woman.
Governor Larry Hogan said his office was "closely monitoring the horrific shooting".
The suspect, who has been identified as Snochia Moseley, was taken to an area hospital with a self-inflicted gunshot wound to her head, Harford County Sheriff Jeffrey Gahler said during a press conference. "She was just shooting", she said as she drove away from a fire station where relatives tried to reunite with loved ones.
The FBI's Baltimore field office earlier tweeted that it was responding and assisting the sheriff's office with an "active shooter" situation.
In Fayette County, Pennsylvania, a gunman shot four people outside a crowded courtroom on Wednesday before being killed by police.