Authorities say he used a stolen assault rifle in Tuesday's shooting spree and was wearing a hockey-style face mask. Clackamas County sheriff's deputies say Roberts had no criminal history.
Police say Roberts had no connection to the two people he fatally shot and wanted to kill as many people as possible. The shooting started around 3:30 p.m. Tuesday at the Clackamas Town Center, which was filled with thousands of holiday shoppers.
The victims were identified as 54-year-old Cindy Ann Yuille, a resident of northeast Portland, and 45-year-old Steven Mathew Forsyth, a resident of West Linn. A third victim, a juvenile, survived the attack and remains hospitalized in serious condition.
Roberts fired dozens of rounds into the crowd. Witnesses said he began shooting at shoppers near the food court until the rifle jammed. Police say Roberts died from a self-inflicted gunshot wound, ending the 90 minutes of terror.
A motive for the shooting was under investigation. Authorities are searching Roberts' home and car.
Meantime, a woman who said she was saved by a young man inside the mall joined her hero on "Good Morning America" Wednesday to talk about the horrifying experience.
"Allan [Fonseca] is my hero because he knew what to do. He said that we needed to evacuate. He took me by the hand and he led me down to the counters and down the escalator and out to safety," said shopper Jocelyn Lay. "This was what is amazing to me. He's my hero because he then turned to me [and said], 'Now that I know you're safe, I'm going to go back and help other people.'"
Fonseca, who works at the Lancome counter in Macy's, returned to the mall and evacuated the lower level of the Macy's store, and then went back up to the "shooting floor" to look for his co-workers.
ABC News contributed to this report.