Karissa Willhite testified she and other staffers were probing Medicare policy issues and not trying to specifically help a wealthy donor on trial for allegedly bribing the Democrat senator from New Jersey.
Prosecutors contend Menendez lobbied on behalf of the donor, Florida eye doctor Salomon Melgen, in exchange for gifts, including free flights on Melgen's private jet and luxury hotel stays in Paris and the Dominican Republic.
Melgen was embroiled in an $8.9 million Medicare billing dispute involving his practice of charging for administering multiple doses from the same vial of medicine. Melgen eventually paid back the entire amount.
On cross-examination, prosecutors presented Willhite with emails to a fellow staffer, including one in which she referred to calling Melgen at home "regarding a Medicare problem we need to help him with."
Willhite also testified Menendez wasn't upset or confrontational during a call with Medicare officials.
Earlier in the trial, one of those officials testified that Menendez became hostile when the official disagreed with him about Medicare policy and that the official understood the call was regarding Melgen's case even though Melgen's name wasn't mentioned.
The trial is in its seventh week. On Monday, the judge declined a request by defense attorneys to dismiss the primary charges against the two men under a 2016 Supreme Court ruling that narrowed the definition of official bribery.
Copyright 2018 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.