The families of the victims who died -- Yuille and Forsyth -- provided brief comments through authorities but asked for privacy as they mourn.
Yuille was remembered as "everybody's friend" who put others first.
Forsyth had two children, a great sense of humor and a zest for life, his family said.
During the shooting, mall patrons said they had no clue where the gunman would fire next.
Entire swaths of Clackamas Town Center became silent except for the rifle blasts and screams. Even the mall's Santa dropped to the ground.
"I thought I was going to die," mall employee David Moran said. "The gunshots were so loud, it was very scary. ... Kids were crying. Parents were crying, too."
Kira Rowland was holding her 6-month-old baby in Macy's when the shots rang out.
"I threw my baby into the stroller and just started running, because everybody was screaming and everybody just started to run," she said.
The gunman wore a hockey mask and jogged through Macy's wielding a rifle, a woman told CNN affiliate KOIN.
As some panicked customers bolted for the exits, others ducked under store counters or hid behind clothing racks.
"I am the shooter," he said as he ran through Macy's, said witness and store employee Austin Patty.
As the shooting started, Patty ran from the store, warning all in earshot that a shooter was loose and ordering them out of the store.
The sheriff's office said a rifle and a mask were recovered from the scene.
Investigators were reviewing surveillance footage to get a better picture of what happened.
Erin Quackenbush-Baker was with her grandmother and three children at a kiosk in the middle of the mall when she heard the shots.
"My 5-year-old was covering her ears and crying. I was frantic to find a place to run, and I looked back -- my son in my stroller and glass is falling over us," she said. "The shots were getting closer."
She added, "I felt like sitting ducks where we were."
During a brief halt in the gunfire, a man helped hustle the family members into a cosmetics store, where they hid for an hour "waiting to see if we were going to be shot or not."
As word spread that the shooter was moving from store to store, customers at Sears burst into tears, Christina Fisher told KOIN.
"We were told to stand in a group by the top of the escalators and stay away from the windows out of the aisle. ... We stood there for probably a good 20 minutes," she said. "All of the sudden, somebody came through with a radio, yelling, 'Get down!' "
As the mayhem unfolded, some customers watched television reports about the shooting from inside the Sears entertainment center, Tylor Pedersen told affiliate KGW.
Antonio Charro spotted a wounded woman near a cell phone store and tried to help.
"She had apparently been shot in the chest, and I couldn't get her turned over to help her," said Charro, who had been shopping at the mall with his daughters. "There was no one around. She wasn't breathing."
Clackamas County Sheriff Craig Roberts said about 10,000 people were in the mall at the time.
No law enforcement officers fired any shots when they arrived, sheriff's Sgt. Adam Phillips said.