Martinez choked back tears as he spoke, then grew angrier as he talked about gun laws and lobbyists.
"The talk about gun rights. What about Chris' right to live?" Martinez said. "When will enough people say: 'Stop this madness! We don't have to live like this! Too many people have died!"
He then punctuated his words as he said, "We should say to ourselves: 'Not! One! More!'" before dissolving into tears and falling to his knees as he stepped from the podium.
Martinez said he talked to his son just 45 minutes before he died inside the IV Deli Mart, where bullet holes and blood could still be seen on Saturday. After already killing five others at his apartment and outside a sorority house, Rodger walked into the deli and shot Michaels-Martinez, authorities said.
Michaels-Martinez was an English major who planned to go to London next year and to law school after graduation, his father said.
He pulled out a photo of his son as a small child in Chicago Cubs baseball uniform and said they used to call him "mini-Sammy Sosa," referring to the former Cubs star.
"Chris was a really great kid," Martinez said. "Ask anyone who knew him. His death has left our family lost and broken."
Friends said Michaels-Martinez, who served as residential adviser at a dorm last year, was the kind of guy who welcomed strangers into his home.
It's not clear whether Rodger knew Katherine Cooper and Veronika Weiss, but they were standing outside a sorority house he was targeting and square in the path of his rampage, authorities said. They became the first ones fatally shot.
Rodger had stabbed and killed three male victims at his apartment already, then drove to the Alpha Phi sorority house, where he fired from across the street and shot three women who were nearby. One of them, whose name has not been released, was injured. Cooper, 22, and Weiss, 19, both UC Santa Barbara students, were killed.
Cooper, who was from Chino Hills, Calif., was about to graduate with a degree in art history. Her friend Courtney Benjamin said Cooper was a painter with an outgoing side.
"She was a self-proclaimed princess and I love her for that," Benjamin said. "And I know she has a crown on her head today."
Weiss was first-year student from Westlake Village.
"She was always a happy person," said Eric Pursley, who worked with Weiss at a Target store in Thousand Oaks last year.
A pile of flowers grew on the lawn Saturday as crying students wandered up to the spot, shook their heads and hugged each other.
UCSB senior Kyley Scarlet, who lives next door and has served as president of her own sorority, said all three who were shot are sorority members, but neither of Alpha Phi nor her own.
Scarlet said she was very disturbed by the video describing his anger at sorority girls.
"It's hard thinking my actions, being part of a sorority, led him to do this," she said. "When I saw that video I was shaking and crying."