A federal judge in San Francisco overseeing lawsuits against Bayer AG’s Roundup weed killer tentatively allowed controversial pieces of evidence in the first phase of the latest trials. A Reuters article says the U.S. District Judge called his decision “probably most disappointing for Monsanto,” the Bayer subsidiary that manufactures Roundup. The company continues to deny the allegations that glyphosate, the key ingredient in Roundup, causes cancer. Monsanto also says decades of independent studies have shown the chemical is safe for human use. With the judge’s decision, plaintiffs can now introduce some evidence of Monsanto’s alleged attempts to ghostwrite studies and influence the findings of scientists and regulators. In his decision, the judge said, “documents showing the company taking a position on the science or a study introduced during the first phase were super-relevant.” Monsanto had argued that much of the evidence was a “sideshow” that would distract jurors from the scientific evidence. Plaintiff’s lawyers contend that some evidence of corporate misconduct was without a doubt linked to their scientific claims of product safety. On Monday, the judge appeared to agree, saying it was difficult to draw the line between scientific evidence and allegations of corporate misconduct. He also questioned whether it would be fair if the jury didn’t get to hear about the company’s alleged attempts to influence scientists.