Howell shot himself between the eyes after he shot Baker, Phenicie said Monday.
"He apparently thought the woman was dead, but she was only hit in the neck and shoulder," he said.
Baker was shot moments after Patrolman Stuart Hannah arrived at the scene. He saw the woman get shot through a window, Phenicie said.
Police were called to the house by Baker's landlord, John Bottomley, after Howell made threats, Phenicie said.
Bottomley lives upstairs in the two-story brick house with his wife, Sandra, Phenicie said.
According to police, Bottomley tried to interfere when Baker told Howell he had to go. Bottomley told Howell that if he didn't leave, he would call the police.
Howell went to his vehicle and came back with a rifle, Phenicie said. Bottomley told Baker and a female friend who was with her to go back into her apartment and lock the door while he ran upstairs to his own apartment to call police, he said.
According to Phenicie, the two women went into a bedroom. Howell smashed in the door and Baker's friend escaped through the bedroom window, he said. When Hannah heard a second shot he went to the window and pulled the wounded Baker out of the house, the chief said.
Meanwhile, another Waynesboro police officer and an officer from Washington Township arrived and entered the house through the door with guns drawn and found Howell's body, he said.
Howell graduated from Waynesboro Area Senior High School in 1989. He was an active member of the Future Farmers of America and an above-average student, said Gerald W. Reichard, one of his teachers.
"He was a hard worker and he was interested in agriculture," Reichard said.
Howell was employed by various local farmers, according to his obituary.
According to his high school yearbook, he hoped to own a farm someday.