Two anti-abortion activists who secretly filmed conversations with Planned Parenthood staff now face felony charges.

On Tuesday, California prosecutors charged David Daleiden of Davis, Calif., and Sandra Merritt of San Jose, Calif., with 15 felonies. That includes one felony count for each of the 14 people they allegedly filmed without permission in three California counties between October 2013 and July 2015. Prosecutors also charged the pair with criminal conspiracy to invade privacy.

The criminal proceedings are a surprise turn in the case, which had been mostly silent since similar charges were dropped in Texas in July. At issue is California’s “two party consent” law, which requires both sides of a conversation to know that they are being recorded for it to be legal, as CNN reported.

“The right to privacy is a cornerstone of California’s Constitution, and a right that is foundational in a free democratic society,” California Attorney General Xavier Becerra said, according to The Washington Post. “We will not tolerate the criminal recording of confidential conversations.”

Mr. Daleiden and Ms. Merritt belong to the Center for Medical Progress, which describes itself as a “group of citizen journalists dedicated to monitoring and reporting on medical ethics and advances.” Under assumed names, the pair allegedly set up a fake company, Biomax Procurement Services, to embark on what they considered an undercover investigation.

In 2014, the complaint indicated, Daleiden and Merritt used their false identities to secretly record participants in the National Abortion Federation conference in San Francisco. In Los Angeles, they met with health-care representatives and secretly recorded them, too, the court filing said.

The videos they produced, which appeared on the group’s website in July 2015, purported to show officials from Planned Parenthood selling fetal tissues. Planned Parenthood has said it does not receive financial compensation, except to cover storage and transport costs, in accordance with federal law, The Christian Science Monitor previously reported. The tissues are directed to medical research, the group said.

The videos quickly ignited debate over Planned Parenthood. Thirteen states conducted investigations, finding that the footage was heavily edited and potentially misleading. In one instance, CNN reported, Daleiden had combined video of a stillborn child, found online, with a voiceover about a Planned Parenthood abortion of a same-age fetus. Planned Parenthood was eventually cleared of all charges.

In Texas, where Daleiden and Merritt had infiltrated a Houston Planned Parenthood clinic, the grand jury impaneled to investigate Planned Parenthood decided to indict Daleiden and Merritt instead. But after an appeal by Daleiden, the charges were dropped. The grand jury had been issued an extension, and so its ability to indict was limited under Texas law, Daleiden’s attorneys argued.

For Planned Parenthood, this case may be an opportunity to see justice served.

"As we have said from the beginning, and as more than a dozen different state investigations have made clear: Planned Parenthood has done nothing wrong, and the only people who broke the law are those behind the fraudulent tapes," Mary Alice Carter, interim vice president of communications for Planned Parenthood, said in a statement.

Daleiden, for his part, described the charges as “bogus” in a statement. And his attorney suggested that the charges infringed on Daleiden’s First Amendment right to free speech.

“It was nothing more than a First Amendment journalist pursuing a good cause and fighting a battle, now a martyr who’s being crushed by the power of the State of California,” Steve Cooley, a former district attorney of Los Angeles who is representing Daleiden, said, The Washington Post reported.

The group has pledged to release more videos "in vindication of the First Amendment rights of all."

This report contains material from the Associated Press.