He was ordered held without bail and is due back in court Oct. 30.
Last year, prosecutors in New York charged Alcala with murder in the deaths of Cornelia Crilley and Ellen Hover.
Crilley, a 23-year-old TWA flight attendant, was found raped and strangled inside her Upper East Side apartment in June 1971.
Hover, also 23 and living in Manhattan, was found dead in Westchester County in 1977.
"Cold cases are not forgotten cases -- our prosecutors, investigators and partners in the NYPD do not give up," Manhattan District Attorney Cyrus R. Vance Jr said in the 2011 release.
In 1978, Alcala was a winning bachelor on the television show "The Dating Game."
At the time, he had already been convicted in the 1968 rape of an 8-year-old girl and served a 34-month sentence, authorities said.
Police found dozens of photographs of women and children in a storage locker Alcala kept in Seattle. The locker also contained earrings belonging to Robin Samsoe, his 12-year-old victim, according to the Orange County, California, district attorney's office.
Authorities asked for the public's help in determining whether any of the people in the photographs were victims of Alcala.
A year before his appearance on the game show, Alcala raped, sodomized and killed 18-year-old Jill Barcomb and 27-year-old nurse Georgia Wixted in California, prosecutors said.
He smashed in Barcomb's face with a rock and strangled her by tying a belt and pants leg around her neck, prosecutors said.
Her body was discovered in a mountainous area in the foothills near Hollywood. Wixted was beaten with the claw end of a hammer and strangled with a nylon stocking, authorities said. Her body was left in her Malibu apartment.
During his appearance on "The Dating Game," Alcala was introduced as a "successful photographer" who might also be found skydiving or motorcycling.
In June 1979, Alcala beat, raped and strangled Charlotte Lamb, a 33-year-old legal secretary, in the laundry room of her El Segundo apartment complex, authorities said.
That same month, he raped and murdered Jill Parenteau, 21, strangling her with a cord or a stocking in her Burbank apartment, they said.
Alcala's blood was collected from the scene after he cut himself crawling out a window, the prosecutor said, adding, "Based on a semi-rare blood match, Alcala was linked to the murder."
He was charged with murdering Parenteau, but the case was dismissed after he was convicted of killing Samsoe in 1979. Alcala approached her at the beach in Huntington Beach and asked her to pose for pictures, authorities said. She did, they said, and Alcala then kidnapped and murdered her, dumping her body in the foothills of the San Gabriel Mountains.
Alcala was convicted of Samsoe's death in 1980 and sentenced to death, but the California Supreme Court overturned his conviction. A second trial, in 1986, also resulted in a death sentence, but it was overturned by the 9th U.S. Circuit Court of Appeals.
As he awaited a third trial, Alcala's DNA was linked to the crime scenes in the Barcomb, Wixted and Lamb cases, and he was charged with killing them and Parenteau.
Jed Mills, who played "Bachelor No. 2" on "The Dating Game" alongside Alcala's "Bachelor No. 1," recalled he had an almost immediate aversion to him. "Something about him, I could not be near him," Mills said last year.
Alcala succeeded in charming bachelorette Cheryl Bradshaw from the other side of the game show's wall. But she declined the date that the show offered them -- tennis lessons, tennis clothes and a trip to an amusement park.