
    Leslie MOLLETT, Appellant v. LEICTH, Captain; Rustin, Warden; Emrick, Deputy; Bohn, Deputy; Donis, Mrj.; Flood, Capt.
    No. 11-4369.
    United States Court of Appeals, Third Circuit.
    Submitted Pursuant to Third Circuit LAR 34.1(a) Dec. 14, 2012.
    Opinion filed: Jan. 25, 2013.
    Leslie Mollett, Frackville, PA, pro se.
    Craig E. Maravich, Esq., Michael H. Wojcik, Esq., Law Department, Office of Allegheny County, Pittsburgh, PA, for Ap-pellees.
    Before: RENDELL, FISHER and GARTH, Circuit Judges.
   OPINION OF THE COURT

PER CURIAM.

Leslie Mollett is a prisoner of the Commonwealth of Pennsylvania. In August 2009, he filed a pro se civil rights complaint, alleging numerous violations of his constitutional rights that occurred during a period as a pretrial detainee (spanning August through December 2007) in the Allegheny County Jai I. The original complaint alleged that Mollett was placed in “unlawful pre-trial detention” as punishment and without receiving a hearing, in violation of the Due Process Clause; it also alleged that his jailers were interfering with his access to the court in his pending criminal case.

In March 2010, before service had been effected, Mollett requested leave to amend his complaint. Denying the formal request as unnecessary, the District Court informed Mollett that he was free to amend his complaint, and emphasized that an amendment must “be filed as a single complete document; it may not simply incorporate or refer to portions of the original Complaint.” In late March, Mollett filed an amended complaint, expanding upon the constitutional allegations contained in the original filing (such as by adding detail about his interactions with staff and claiming that he had also been denied necessary medical treatment); but while the original complaint requested declaratory relief and monetary damages, the amended complaint sought only declaratory and injunctive relief, dropping the request for damages.

The defendants moved to dismiss, arguing that Mollett’s complaint was defective on a number of grounds; significantly, they identified a possible mootness problem in the relief sought “because plaintiff is no longer incarcerated at the Allegheny County Jail as a pre-trial detainee.” In response, Mollett asked the District Court to grant him further leave to amend to correct the deficiencies in his amended complaint; specifically, he requested the Court’s permission to “withdraw the prayer for injunctive relief as moot,” but insisted that he remained “entitled to declaratory relief.” Pi’s. Br. in Supp. 13, ECF No. 39.

The District Court entered its opinion in November 2011. The Court reached the substance of Mollett’s various claims, but also determined that the relief he requested was not available; Mollett was no longer in pre-trial custody and thus was entitled to neither injunctive nor declaratory relief. The Court said nothing about amendment in its opinion. Mollett timely appealed.

“Under Article III, section 2 of the U.S. Constitution, federal judicial power extends only to cases or controversies. If a claim does not present a live case or controversy, the claim is moot, and a federal court lacks jurisdiction to hear it.” United States v. Virgin Islands, 363 F.3d 276, 284-85 (3d Cir.2004) (footnote omitted). “It is a basic principle of Article III that a justiciable case or controversy must remain extant at all stages of review, not merely at the time the complaint is filed.” United States v. Juvenile Male, — U.S. -, 131 S.Ct. 2860, 2864,180 L.Ed.2d 811 (2011) (per curiam) (citations, quotations omitted). In Steel Co. v. Citizens for a Better Environment, 523 U.S. 83, 118 S.Ct. 1003, 140 L.Ed.2d 210 (1998), the United States Supreme Court disapproved of the practice of assuming “hypothetical jurisdiction” to reach the merits of cases where Article III jurisdiction is either clearly lacking or questionable; “[ujnder the rule of Steel Co., when a court lacks jurisdiction its ‘only function ... is that of announcing the fact and dismissing the cause’ as any further discussion would amount to an advisory opinion.’” Treasurer of N.J. v. U.S. Dep’t of the Treasury, 684 F.3d 382, 394 n. 14 (3d Cir.2012) (quoting Steel Co., 523 U.S. at 93-94, 118 S.Ct. 1003). Thus, determining constitutional “subject-matter jurisdiction necessarily precedes a ruling on the merits.” Ruhrgas AG v. Marathon Oil Co., 526 U.S. 574, 584, 119 S.Ct. 1563, 143 L.Ed.2d 760 (1999); see also Unala-chtigo Band of the Nanticoke Lenni Lenape Nation v. Corzine, 606 F.3d 126, 130 (3d Cir.2010) (observing that an advisory opinion issued in the absence of jurisdiction “ignore[d] the dictates of Article III”); Burkey v. Marberry, 556 F.3d 142, 149 (3d Cir.2009).

In this case, Mollett’s amended complaint, which superseded the original, see ConnectU LLC v. Zuckerberg, 522 F.3d 82, 91 (1st Cir.2008), was jurisdictionally defective at the moment it was filed, and “when a plaintiff files a complaint in federal court and then voluntarily amends the complaint, courts look to the amended complaint to determine jurisdiction,” Rockwell Int’l Corp. v. United States, 549 U.S. 457, 473-74, 127 S.Ct. 1397, 167 L.Ed.2d 190 (2007). The request for injunctive relief attacked conduct associated specifically with the Allegheny County Jail, but Mol-lett had long since been convicted, sentenced, and transferred. From that moment forward, the District Court was plainly unable to fashion meaningful in-junctive relief. See Abduk-Akbar v. Watson, 4 F.3d 195, 206 (3d Cir.1993). Mol-lett’s request for declaratory relief fared similarly, because “in the context of an action for declaratory relief, a plaintiff must be seeking more than a retrospective opinion that he was wrongly harmed by the defendant.” Jordan v. Sosa, 654 F.3d 1012, 1025 (10th Cir.2011). Mollett’s transfer rendered the case moot; and because it was unable to grant the relief sought, the District Court lacked jurisdiction over the merits of the case. Id. at 1024-25.

On appeal, Mollett does not challenge the District Court’s ruling regarding mootness or its failure to allow amendment except as to his desire to amend his complaint as to a Fourth and Fifth Amendment claim. Given this, we see no reason to disturb the District Court’s conclusion that his request for a declaratory judgment and injunction are no longer cognizable, and we will therefore affirm. 
      
      . Mollett was convicted and received a life sentence. See CP-02-CR-0000254-2006; see generally Commonwealth v. Mollett, 5 A.3d 291 (Pa.Super.Ct.2010), appeal denied, 609 Pa. 686, 14 A.3d 826 (2011). His conviction. sentence, and transfer out of pre-trial custody in the Jail occurred long before he commenced this federal litigation; he is currently imprisoned at SCI Frackville.
     
      
      . The parties consented to the jurisdiction of a Magistrate Judge.
     
      
      . We have jurisdiction under 28 U.S.C. § 1291. Our review is plenary. Capogrosso v. Sup. Ct. of N.J., 588 F.3d 180, 184 (3d Cir.2009) (per curiam).
     