Mr. Snyder, who said Westboro members turned his son’s funeral in Westminster, Md., into a “media circus,” is seeking unspecified damages in the jury trial, which is expected to end next week. In opening statements, his lawyer said church members had shown no regret for the protest, which he said had left Mr. Snyder with depression and health complications from diabetes.

Image Westboro Baptist Church members say American troops die as punishment for homosexuality. Credit... Christopher Berkey/Associated Press

“They wanted their message heard, and they didn’t care who they stepped over,” Mr. Snyder testified Wednesday, according to The Associated Press. “My son should have been buried with dignity, not with a bunch of clowns outside.”

Experts say the case is a test of the limits of free speech.

Similar demonstrations by Westboro Baptist Church members have prompted several states, including Maryland, to establish limits on funeral protests.

Ronald K. L. Collins, a scholar at the First Amendment Center in Washington, said such restrictions pose certain dangers, however. “The dangerous principle here is runaway liability in a way that would put the First Amendment in serious jeopardy,” Mr. Collins said. “I dread to think what it would do to political protests in this country if it were allowed the win.”

Judge Richard D. Bennett, who is hearing the case, told the nine jurors that there are limits on free speech protection, listing categories that include vulgar, offensive and shocking statements, and instructed jurors to decide “whether the defendant’s actions would be highly offensive to a reasonable person, whether they were extreme and outrageous, and whether these actions were so offensive and shocking as to not be entitled to First Amendment protection,” according to The A.P.