By Amy Kawata

BALTIMORE (WJZ) —  Baltimore police say four people were shot Saturday in three separate shootings. Investigators believe the same person was responsible for the rampage that ended in three dead, including the gunman.

City leaders say they are thankful for the off-duty officer who jumped into action, saving others from getting hurt.

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Tonight, police are still searching for answers.

A deadly shooting spree across East Baltimore.

“It’s unbelievable, this is not something you hear about that happens every day,” said Arden Farrell, resident in O’Donnell Heights.

Ending with an officer-involved shooting at a barbershop in O’Donnell Heights.

“I’m glad I wasn’t there at the time,” said Farrell.

Customers like Arden Farrell are left in shock.

“I was actually going to come down here yesterday, so I’m pretty surprised this whole thing happened,” said Farrell.

Baltimore police say it all started just after 2:30 in the afternoon Saturday on East Oliver St., where officers responded to a report of a shooting and found a 37-year-old man suffering from gunshot wounds.

The victim was then transported to the hospital in critical condition.

“Apparently there was an argument that ensued, at some point, this perpetrator produced a firearm and shot an individual who is the victim of a non-fatal shooting,” said Michael Harrison, Baltimore Police Commissioner.

Police say the suspect then drove to Eastern Avenue, where another argument led to another shooting, killing one person.

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“I was in shock (but to) and I saw the blood on the sidewalk,” said Jesus Romero, a business owner.

About 30 minutes later, detectives say the suspect drove to his final stop at this barbershop on O’Donnell St., walked inside the business and shot and killed a barber who was working there.

He was then met by an armed off-duty officer who was getting his hair cut.

“That member of our department was armed while off-duty and in plain clothes. Responding to the shooting immediately, and with great bravery produced his firearm and fired at the perpetrator, striking the perpetrator,” said Harrison.

Police say the suspect was killed.

“That was total luck there,” said Rich Jacobson, who lives in O’Donnell Heights.

“He was just in the right place at the right time,” said Farrell.

As detectives continue to investigate a possible motive, Mayor Brandon Scott commended the officer for his swift actions.

“Petty, minor stupid disputes, ending up with people losing their lives. And we have to be understanding of that and again, grateful that our officer was here,” said Scott.

Police say the officer who shot and killed the suspect was not injured in this incident.

The investigation is now being handled by the attorney general’s office.

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Anyone with information on any of the three shootings on Saturday is urged to contact Baltimore police.