A California scholar is the next witness in the trial over the future of Michigan's ban on gay marriage.
Gary Gates of the Williams Institute at UCLA law school co-authored a book on demographics of the gay and lesbian population. He's used census data to study the characteristics of same-sex couples.
Gates is expected to testify Thursday in Detroit federal court. Detroit-area nurses Jayne Rowse and April DeBoer are asking a judge to overturn a 2004 constitutional amendment that bans same-sex marriage. They say it violates their rights under the U.S. Constitution.
Rowse and DeBoer want to marry and jointly adopt each other's children. They can't take those steps under Michigan law.
State attorneys want the judge to uphold the will of voters.