Houston’s top prosecutor said Friday that a substance recovered from the work van of a Mexican immigrant killed by an Immigration and Customs Enforcement agent tested negative for illicit drugs. The finding removes one of the claims tied to the case and adds a new layer to the scrutiny surrounding the fatal encounter.

According to the prosecutor’s office, laboratory testing did not identify the material as an illegal narcotic. That development is significant because it undercuts suggestions that drugs were involved based on what was found in the van.

The case has drawn attention because it involves a fatal shooting by a federal immigration agent and questions about what happened before the man was killed. With the substance now ruled out as an illicit drug, investigators and the public are likely to focus even more closely on the evidence surrounding the incident itself.

Authorities have not resolved the broader issues raised by the shooting, but the prosecutor’s statement narrows one disputed point. For now, the lab result stands as an important update in a closely watched Houston case involving ICE enforcement and a man’s death.