On Tuesday, the Center for Medical Progress—an anti-abortion group that has little to do with actual medicine—released the eighth in its series of undercover videos purporting to show that Planned Parenthood officials have profited from illegal sales of fetal tissue. The videos have prompted protests at clinics across the country, congressional investigations, and inquiries at the state level. They’ve also sparked a renewed effort to cut off government funds for the organization, whether Medicaid reimbursements or other sources of state and federal money. Four more videos are reported to be coming, with the last slated to hit close to the deadline for funding the federal government.

The latest video, like the ones before it, does not expose any clear evidence of wrongdoing by Planned Parenthood. Nor have any of the state investigations. On the other hand, a new forensic analysis of five of the videos has found evidence that they have been “manipulated” and “deceptively edited,” according to a letter sent Thursday by Planned Parenthood to congressional leaders. The review, conducted by the research firm Fusion GPS and verified by independent video and transcription experts, concluded that the videos—even the long versions CMP claims are full-length—“do not present a complete or accurate record of the events they purport to depict,” and so are not reliable as evidence in a legal context or in a journalistic sense.

Analysts identified at least 42 places in the videos where content had been edited out, though the splices are not apparent to a casual viewer. The shorter tapes had been “severely” altered, Fusion GPS co-founder Glenn Simpson said Thursday on a conference call with reporters, in at least one case so that a question from one of the undercover anti-abortion activists was linked with an unrelated answer. One video was edited so that a Planned Parenthood staffer in Texas speaking about lab protocols to keep tissue intact seemed to be speaking about changing abortion procedures to do so. Transcripts provided by CMP were “sloppy at best,” and at worst represented “wishful thinking” about what was said, according to Simpson. Quotes, including at least one highlighted in the media, were improperly attributed.

Because the unedited footage is not available, it’s hard to know the full extent of the manipulation. The audio compression that occurred when the videos were uploaded to the web also made analysis more difficult. But it is clear that in order for a congressional inquiry to be credible, investigators would have to obtain the original, unaltered material. The bottom line, said Simpson, is that “Anytime someone has made undisclosed changes to an audio or video file, that renders the file unreliable.”

The forensic analysis should clarify that the scandal is not Planned Parenthood’s participation in tissue donation for medical research. It’s the surreptitious campaign undertaken by CMP to attack the healthcare provider, possibly in collusion with some members of Congress. Some Democrats have already asked Attorney General Loretta Lynch to investigate CMP for fraud and other misconduct, but the Justice Department has not indicated whether it will.

The evidence of manipulative editing probably won’t quiet the cascade of anti-abortion outrage provoked by the videos. Politicians looking for a reason to call for defunding the organization or to launch investigations will continue to do so. In campaign season, the occasion to rile up the evangelical base is a gift. So far, Ted Cruz is the shrewdest opportunist. On Tuesday, he spoke on a conference call with pastors from around the country and asked them to use the pulpit to build support for dragging the Planned Parenthood debate into upcoming negotiations over a must-pass budget bill; considering his lackluster poll numbers, Cruz appears to be hoping that another government shutdown will shake the shadow of Donald Trump.

At some point the charade will end, practically speaking: it’s hard to imagine how members of Congress could argue for the integrity of their investigations if they don’t obtain unaltered videos, and it’s unlikely that the original footage contains any of the evidence against Planned Parenthood that the heavily doctored versions lack. But that doesn’t mean it’s going to happen anytime soon.