G.R. No. 237428 - Republic vs. Sereno

Maria Lourdes P. A. Sereno (respondent) was employed as a faculty member of the University of the Philippines (UP) College of Law from November 1986 to June 2006, initially as temporary and then permanent faculty.
While in government service, respondent was required to file Statements of Assets, Liabilities, and Net Worth (SALNs) annually, yet records showed many years (especially 1986-2006) had no SALNs filed.
Respondent concurrently served as legal counsel to the Republic of the Philippines in international arbitration cases from 2003 to 2009.
In July 2010, respondent applied for Associate Justice of the Supreme Court and submitted certain SALNs, but her submission for that period was incomplete or unsubscribed.
In 2012, respondent applied for Chief Justice of the Supreme Court, submitting SALNs only for the years 2009-2011 and a waiver for bank secrecy. The Judicial and Bar Council (JBC) required all previous SALNs for those in government service, but respondent submitted a letter stating most of her records were “infeasible” to retrieve due to age.
The JBC included respondent in a shortlist of nominees despite incomplete SALNs submitted, apparently unaware of the letter’s full implication.
On August 24, 2012, respondent was appointed and took the oath as Chief Justice by then President Benigno C. Aquino III.

An impeachment complaint was filed against respondent for culpable violation of the Constitution, corruption, high crimes, betrayal of public trust, and inaccurate SALN disclosures.
During congressional hearings, evidence showed respondent failed to file SALNs regularly during her UP faculty years and did not fully disclose fees from her legal counsel work.
Following hearings, the Solicitor General (representing the Republic) filed a petition for quo warranto before the Supreme Court seeking to nullify respondent's appointment for failing to prove the required integrity qualification.
Multiple motions to intervene and for the inhibition of certain Justices were filed; all were denied for lack of sufficient legal interest or basis.
Respondent denied allegations, argued that only impeachment can remove an impeachable officer, claimed the petition was time-barred, and asserted the JBC’s sole authority over judicial qualifications.
The Supreme Court conducted special oral arguments to hear the parties and assess issues.

Can the Supreme Court assume jurisdiction and give due course to the petition for quo warranto against an impeachable officer who also faces impeachment proceedings?
Does the Court’s exercise of jurisdiction over quo warranto violate the doctrine of separation of powers or judicial independence?

Is the petition for quo warranto time-barred under Rule 66, Section 11 of the Rules of Court, or is the one-year period not applicable to the State?

Is the determination of a judicial candidate’s eligibility and integrity exclusively vested in the JBC and the appointing authority, thus a political question outside the Court’s review?
Did respondent fail to regularly file SALNs as required by the Constitution and laws?
Does respondent’s failure to submit all SALNs to the JBC disqualify her for nomination?
If found ineligible, can nomination by the JBC and appointment by the President cure such ineligibility?