A former aide to U.S. Sen. Bob Menendez testified in federal court in Newark Monday that it was not uncommon for the New Jersey Democrat to advocate on behalf of visa applicants, something prosecutors allege he did in exchange for a bribe in 2010.

The testimony capped off day three of the corruption trial of Menendez and his friend, wealthy Florida ophthalmologist Salomon Melgen, who each face about a dozen counts of bribery, conspiracy, and fraud. Both have pleaded not guilty.

Mark Lopes, a former senior policy adviser to Menendez, said he made phone calls and sent emails to consular officials in 2008 hoping to smooth the visa application process for three women who were Melgen's girlfriends.

The prosecution alleges that Melgen bribed Menendez with free gifts and trips so he would push for the approval of travel visas for Melgen's girlfriends (among other favors). Menendez exerted more effort on the matter than he would have for any other constituent, government attorneys said.

Prosecutor J.P. Cooney pointed to an email Lopes sent after two of the applications were approved despite signs that they might be denied: "In my view this is only due to the fact that RM intervened," Lopes wrote, referring to his boss' initials.

On cross examination, however, Lopes acknowledged that it was common for Menendez to advocate on behalf of visa applicants he knew personally or as constituents or acquaintances.

Raymond Brown, a defense attorney for Menendez, presented a letter the senator had written in 2008 to support the visa applications of a Colombian family hoping to come to the U.S., a case that was unrelated to the trial.

Over the objections of prosecutors, Judge William H. Walls allowed the letter into evidence. "The jury has a right to consider whether what the senator did under similar circumstances more or less contemporaneously to the alleged offense is just commonplace," Walls said, or that "this time it was criminal."

Lopes assured the jury that Menendez never asked him to do anything illegal, including calling ambassadors and consul generals on behalf of visa applicants.

Earlier in the day, Andrew Thomas, a vice president at American Express, testified about how Melgen used credit card points to book a Paris hotel room for Menendez in 2010.

Prosecutors claimed that Menendez induced Melgen to book the room and then made an empty promise to pay him back in AmEx points. Instead, they say, Menendez later redeemed his points for a Weber Genesis grill, which was sent to a New Jersey address, and never paid his debt.

Defense attorneys countered that it was typical for the two friends to give each other gifts expecting nothing in return. Brown, one of Menendez's attorneys, tried to introduce credit card bills showing that the senator had paid for his own hotel rooms in the years just before and after 2010, attempting to beat back the prosecution's contention that Menendez had gotten used to a lifestyle he could not afford.

This time, Judge Walls turned him down. "That [Menendez] may have paid for a room in 2007 really has no relevance as to whether he asked his buddy to pay for his room in 2010," Walls said.

Although Menendez sat quietly at the defense table throughout Monday's testimony, he had speaking engagements before and after the five-hour proceedings.

Around 8 a.m., he made remarks at a ceremony marking the 16th anniversary of the 9/11 attacks at the Essex County September 11th Memorial in West Orange. He was also scheduled to speak at the Bayonne Interfaith 9/11 Memorial Service Monday evening.