Testimony ended in federal court in San Francisco Wednesday in a groundbreaking two-and-a-half week trial on whether California's ban on same-sex marriage is constitutional.
The case before U.S. District Judge Vaughn Walker has been the first federal trial in the nation on a U.S. constitutional challenge to a prohibition on gay marriage.
The outcome is expected to be appealed to the U.S. Supreme Court.
Walker, who will rule without a jury, said he will set a date for closing arguments after reviewing the evidence.
He told attorneys, "I'd like to take some time to go over all this material. I will probably key up some questions that have come to the fore."
The judge is expected to issue a written ruling sometime after hearing the arguments.
That hearing may not occur until March at the earliest, because Walker gave attorneys until Feb. 26 to submit papers tying the trial evidence to proposed factual findings and legal conclusions.
The trial was on a lawsuit in which a lesbian couple from Berkeley and a gay couple from Burbank claim that California's ban, enacted by voters as Proposition 8 in 2008, violates their federal constitutional rights to due process and equal protection.
Proposition 8, approved by a 52 percent majority of voters, provides that "only marriage between a man and a woman is valid or recognized in California."
The proposition has been defended in court by its official sponsors, who say the measure is a reasonable way of preserving the traditional definition of marriage and promoting the welfare of children.
At a news conference after the trial testimony ended at noon Wednesday, plaintiffs' attorney David Boies said he thought the couples had proved their claim that Proposition 8 can't be justified.
"We have exposed publicly that there simply is no basis for prohibiting gay and lesbian people from getting married. It doesn't harm anyone," Boies asserted.
Andrew Pugno, a lawyer for Proposition 8 sponsors, claimed in response that the defenders had shown voters had a rational basis for approving the measure.
"The rational reason," Pugno said, "is that the best thing for children is to have both a mother and a father."