DeCosta said when he got to the food court, "I saw a gentleman face down, obviously shot in the head."
"A lot of blood," DeCosta said. "You could tell there was nothing you could do for him."
He said he also saw a woman on the floor who had been shot in the chest.
Austin Patty, 20, who works at Macy's, said he saw a man in a white mask carrying a rifle and wearing a bulletproof vest. There was a series of rapid-fire shots in short succession as Christmas music played. Patty said he dove for the floor and then ran.
His Macy's co-worker, Pam Moore, told the AP the gunman was short, with dark hair.
Kira Rowland told KGW-TV that she was shopping at Macy's with her infant son when the shots started.
"All of a sudden you hear two shots, which sounded like balloons popping," Rowland told the station. "Everybody got on the ground. I grabbed the baby from the stroller and got on the ground."
Rowland said she heard people screaming and crying.
"I put the baby back in the stroller and ran," Rowland said.
Kaelynn Keelin was working two stores down from Macy's when the gunfire began. She watched windows of another store get shot out. She and her co-workers ran to get customers inside their own store to take shelter.
"If we would have run out, we would have run right into it," she said.
Shaun Wik, 20, was Christmas shopping with his girlfriend and opened a fortune cookie at the food court. Inside was written: "Live for today. Remember yesterday. Think of tomorrow."
As he read it, he heard three shots. He heard a man he believes was the gunman shout, "Get down!" but Wik and his girlfriend ran. He heard seven or eight more shots. He didn't turn around.