In 2011, just months after joining the Senate, Sen. Marco Rubio (R-Fla.) missed three hearings called in the wake of the killing of Osama bin Laden, according to a review of attendance records.

Rubio has kept a busy political travel schedule since arriving in Washington -- and his activities off the Hill have made him the most-absent senator, according to a review of records by GovTrack, a nonpartisan group that catalogs government activity.

Since his arrival in D.C., he's been a member of the Senate Foreign Relations Committee and the Intelligence Committee -- two prominent  assignments for a freshman senator. When Republicans took Senate control in January, he became chairman of a Foreign Relations subcommittee on the Western Hemisphere, giving him an official perch to criticize the Obama administration's outreach to Cuba and its response to ongoing turmoil in Venezuela. Once he launches his presidential campaign on Monday, as expected, he's likely to tout his experience dealing with foreign policy and intelligence matters on both the Foreign Relations and Intelligence committees.

But in the days after bin Laden's death on May 2, he was a no-show at several Foreign Relations hearings.

On May 3, the committee held a previously-scheduled meeting to discuss ongoing military operations in Afghanistan. Just 11 of the 19 committee members showed up and Rubio was among those absent, according to records.

When he opened the hearing, then-Sen. John F. Kerry (D-Mass.), who chaired the panel, said that "One of the reasons we’re here this morning is to examine how Osama bin Laden’s death affects the conflict in Afghanistan and its implications for our upcoming troop withdrawal, our transition strategy, and our partnerships in the region."

Agreeing with Kerry, then-Sen. Richard Lugar (R-Ind.) said that "These hearings are especially timely...given the killing of Osama bin Laden."

So where was Rubio? Absent in Washington, he instead received a secure briefing at SOUTHCOM headquarters in Miami, according to his aides.

On May 4, Rubio attended a closed-door briefing for the Intelligence and Armed Services committees regarding the bin Laden raid, according to news reports at the time.

But on May 5, the Foreign Relations panel met again to review U.S.-Pakistan relations. Twelve members were present -- but not Rubio, records show. The hearing explored what, if anything, Pakistani officials might have known about bin Laden's whereabouts and also reviewed the U.S. relationship with Pakistan.

On May 10, at the third of six hearings that month on Afghanistan and Pakistan, records again show that Rubio wasn't there.

Brooke Sammon, a Rubio spokeswoman, didn't say late Friday why Rubio skipped the hearings. But in a statement, she said that "As a member of both the Senate Foreign Relations and Intelligence committees, Senator Rubio receives frequent briefings and reads intelligence reports on a regular basis in addition to attending most hearings. If he misses a hearing, he's briefed on the material covered."

Aides also noted that some of the hearings didn't include witnesses from the Obama administration, who would have been able to provide more tangible information on the raid and its aftermath.

After bin Laden's death, Rubio issued a statement congratulating "our intelligence and military communities on this monumental operation." He added that "While this diabolical terrorist's death at America's hands is a moment to celebrate, we must never forget the serious terrorist threats that remain and will demand an enduring vigilance."

In recent weeks as he began preparing to run for president, Rubio missed other hearings on newer world threats. He skipped three briefings regarding the Islamic State terror group -- one held by the Foreign Relations panel and two closed-door meetings organized by the Intelligence Committee, according to BuzzFeed.

On Monday, the Senate is scheduled to return from a two-week recess and hold votes at 5 p.m.

But Rubio will be absent and in Miami, launching his presidential campaign.