According to the criminal complaint filed by the Marin County District Attorney's office, Lampley is the accused trigger man in Steve Carter's murder. All three are charged with murdering Canadian tourist Audrey Carey.
VIDEO: Canadian tourist identified as San Francisco homicide victim
The three young drifters appeared in court shackled with their heads shaved. Police in Portland reportedly cut their hair before extraditing them because of a medical condition. A source said they were infected with lice.
Alligood entered the court room first. She looked nervous and a little surprised to see the packed courtroom. "I told her I would be getting an attorney for her and just to take a deep breath when she was anxious and we will get somebody to help her," attorney James Nielson said.
Nielsen sat next to her and whispered to her during the hearing. "When she was anxious or feeling really tense I told her to just relax, I mean again she's 18, very young," he said.
Nielson is not her attorney, but is part of a program that will find one for her and co-defendant Angold.
The court appointed public defender David Brown to represent Lampley. "We do plan to mount a vigorous and ethical defense on our young client's behalf," Brown said.
Court documents reveal a rap sheet for the suspects that include drugs, weapons and theft cases. Lampley, Alligood and Angold face two first-degree murder charges and second-degree robbery.
Under an agreement with San Francisco authorities, Marin County is prosecuting both the murders of Carey and Carter.
The suspects are charged with killing backpacker Audrey Carey, 23, who was found shot in the head in Golden Gate Park on Oct. 3, and tantric yoga teacher Steve Carter, 67, whose body was found near a popular hiking trail on Oct. 5.
They are charged with murder with special circumstances that include lying in wait for the victims, making them eligible for the death penalty.
San Francisco police Cmdr. Toney Chaplin said both victims were shot with the same handgun, which was reported stolen Oct. 1 from an unlocked car in San Francisco Fisherman's Wharf neighborhood.
The three suspects have "no fixed address," Marin County sheriff's Lt. Doug Pittman said. They were arrested outside a Portland, Oregon, soup kitchen last week.
They were found with the stolen gun, Carter's Volkswagen station wagon and Carey's tent, sleeping bag, day pack and other possessions, including her passport and airline tickets, according to investigators and the criminal complaint.
Carey had just embarked on a backpacking trip and had camped in Golden Gate Park during the popular Hardly Strictly Bluegrass music festival.
Two days later, a hiker found Carter's body and his wounded dog in Marin County, about 20 miles north of San Francisco. The pet is expected to survive, and all three are charged with animal cruelty.
Followers credited Carter with improving their romantic relationships by teaching tantra, a philosophy of meditation, yoga and sexuality famously embraced by rock star Sting.
Berberian said a decision on whether to pursue the death penalty will be made later. He said the office conducts a "detailed review process" before deciding whether to ask a jury and judge to sentence a defendant to death. California hasn't executed anyone since 2005.
Arraignment was postponed because Angold and Alligood have not been appointed defense attorneys.
ABC7 News Reporter Amy Hollyfield and The Associate Press contributed to this story.