MARTINEZ -- The respective siblings of slain Caltrans toll taker Deborah Ross and Golden Gate Transit bus driver Ersie "Chuckie" Everette on Tuesday echoed each other on the witness stand: Nathan Burris is a coward.

Unknown to each other before they were united in grief by the Aug. 11, 2009 Richmond-San Rafael Bridge toll plaza killings, Ross' sister, Jane Gray-Walker, and Everette's brother, Ron Everette, were the final witnesses for the prosecution in the penalty phase of Burris' capital trial.

Burris, a 49-year-old Richmond man, was convicted last week of two counts of first-degree murder and special circumstances for the shotgun shootings that he says were justified because he suspected the victims had become romantically involved after Ross ended their 14-year relationship. Burris, acting as his own attorney, will present his penalty phase defense Wednesday, after which the jury will decide whether to recommend a death sentence or life in prison without the possibility of parole.

"He fooled the whole family. We had no idea he was that treacherous, that lowdown and dirty," Gray-Walker said. "He's a lying coward. He always has been, and we found that out the day he took my sister's life and that man's.

"I don't know why he did what he did, but she did everything she could to help him," Gray-Walker said.

Everette, a 58-year-old San Leandro resident, and Ross, 51, of Richmond, each grew up in large families in Oakland and joined the work force in their teens, with Everette serving in the U.S. Marine Corps and Ross joining the Conservation Corps. Both were described as decent, caring people who were devoted to their church and families.

In the guilt phase of the trial, the jury saw pictures of the victims' lifeless bodies after Burris ambushed Everette in the toll plaza parking and Ross in her toll booth. On Tuesday, the prosecutor shared cherished family photos like Everette on his last Christmas Day, and with his brothers and mother on Mother's Day, and Ross with her daughter, sisters, nieces and nephews at reunions and vacation cruises.

"(I'm) very emotional. It's not because of the murderer. It's because I'm missing my brother, and the memories," Ron Everette testified. "I don't believe, at some points, he's dead. It's like, I'm waiting for him to call me.

"It's an empty feeling, frustrating to realize you don't have him any more," Ron Everette said.

Both siblings said it was hard to comprehend the circumstances surrounding the deaths and that they hated Burris for taking the lives of their loved ones.

"I didn't know it was Nathan. I just knew, whoever it was, I was gonna find them," Ron Everette said, recalling his reaction when he first heard of his brother's murder.

"You're lucky you didn't," Burris replied.

Contact Malaika Fraley at 925-234-1684. Follow her at Twitter.com/malaikafraley.