SPRING HILL — A string of shootings in Pasco and Hernando counties Thursday left two people dead, including the shooting suspect, and another person seriously injured, authorities said.

Theodore Antonia Parker, 59, shot at a woman at her home on Chestnut Drive in Hudson about 2:40 p.m., Pasco County sheriff's officials said. The woman sustained a bullet graze wound on her neck, Pasco sheriff's officials said, and called 911. The woman, whose identity was not released, was expected to survive, Pasco officials said.

About five minutes later, Parker arrived at a home on Olson Road in Spring Hill, where he shot and killed a man, Hernando Sheriff Al Nienhuis said in a video posted to the agency's Facebook account. Detectives did not release the identity of the shooting victim.

Investigators believe Parker knew the people at both locations, and neither of the first two shootings was random.

The violence didn't stop there.

Hernando deputies believe Parker went minutes later to a nearby smoke shop at 2993 Commercial Way. Deputies believe he tried to rob the store.

Parker shot the owner, who had his own gun and returned fire, hitting Parker, Nienhuis said. The store owner, whose name deputies withheld, was taken to a hospital with significant injuries but had been talking with deputies. He was in critical condition Thursday night.

"We believe it was totally self-defense," Neinhuis said.

Parker left the store after being shot and collapsed in the parking lot outside the store owner's car. He was pronounced dead at a hospital.

Investigators did not know if Parker had been a customer of the smoke shop, but they do not think he knew the owner. They were still working to determine what fueled the rampage.

"It was a pretty harrowing 15 or 20 minutes," Nienhuis said.

Correction: A previous version of this story misstated the age of Theodore Parker.