The United States placed Angela Johnson, the defendant in this case, in a small jail where it was likely that she would encounter an inmate, Robert McNeese, who had acted as an informant for the government in the past. Mr. McNeese was able to elicit damaging information from Ms. Johnson about her involvement in the murder of three government witnesses and one witness’s two young daughters. Ms. Johnson moved to suppress Mr. McNeese’s testimony on the ground that he was a government agent when he talked to her, and that use of the testimony against her would therefore violate her Sixth Amendment right to counsel. The District Court granted her motion, and the government appealed. We hold that the District Court misconstrued our precedent in reaching this conclusion. We reverse the District Court’s order suppressing the testimony in question and remand this case for further proceedings consistent with this opinion.
I.
In 1993, a grand jury indicted Dustin Honken for conspiracy to distribute methamphetamine. A witness who was to testify against him disappeared, as did the witness’s girlfriend and her two young daughters. Later, another witness in the case vanished. By March of 1995, the government was forced to abandon its case against Mr. Honken because of a dearth of witnesses to testify against him. However, the government continued its investigation. Angela Johnson, Mr. Honken’s girlfriend at the time of the disappearances, was indicted in July of 2000 for aiding and abetting the murder of the five witnesses, aiding and abetting the solicitation of the murder of witnesses, and conspiring to interfere with witnesses. 18 U.S.C. §§ 1512, 373, 371.2 She was arrested on July 30, 2000. The government had Ms. Johnson sent to the Benton County Jail in Iowa.
The government knew that Robert McNeese, an inmate with a history of trading information he gathered in prison for favorable treatment, was already housed at the Benton County Jail. By August 7, 2000, Mr. McNeese had established contact with Ms. Johnson. Thereafter, they communicated openly or surreptitiously as opportunities presented themselves. It is clear that some of the jailers knew that *920they were in contact and made only token efforts to sever the link between them. Detective Wright, who was in charge of investigating incidents at the jail, learned of these exchanges and ordered Mr. McNeese to stop communicating with Ms. Johnson. Detective Wright had Ms. Johnson moved to a new cell, but the move merely altered her channels of communication with Mr. McNeese, not the frequency of contacts.
A month later, Mr. McNeese told a prison official that he had convinced Ms. Johnson that he could get a prisoner in another jail to confess to the five murders she was charged with, so that Ms. Johnson could sue the government for false imprisonment and split the proceeds of such a suit with Mr. McNeese. Mr. McNeese had also obtained some incriminating admissions from Ms. Johnson. The official told Mr. McNeese not to deal with Ms. Johnson until the officer could get instructions on how the situation should be handled.
Five days later, on September 11, 2000, Mr. McNeese met with officials to receive “listening-post” instructions regarding Ms. Johnson. All parties agree that Mr. McNeese was acting as a government agent from this point forward. The next day he signed a plea agreement that had been drafted back on September 7, 2000, in another case. This agreement required that Mr. McNeese cooperate in cases that might arise in the Northern District of Iowa. Two weeks later, Mr. McNeese disclosed to the government the information that he had extracted from Ms. Johnson while they had been in jail together.
The government filed a notice of intent to use Ms. Johnson’s disclosures to Mr. McNeese and evidence derived therefrom. Ms. Johnson moved to suppress that evidence. She pointed out that she was under indictment (the first of the two indictments involved in this case) at the time of her conversations with Mr. McNeese. Accordingly, her right to counsel under the Sixth Amendment had attached. She asserted, moreover, that Mr. McNeese was a government agent at the time of all of his conversations with her, and that he had deliberately elicited from her the information that the government sought to introduce. In support of this contention, Ms. Johnson cited Massiah v. United States, 377 U.S. 201, 84 S.Ct. 1199, 12 L.Ed.2d 246 (1964). After an evidentiary hearing the District Court filed an opinion granting Ms. Johnson’s motion. United States v. Johnson, 196 F.Supp.2d 795 (N.D.Iowa 2002). The major issue discussed in the opinion was whether Mr. McNeese was a government agent before September 11, 2000. The District Court held that he was. From the order granting Ms. Johnson’s motion to suppress, the United States appeals.
II.
The leading Supreme Court case in the area is, as indicated, Massiah v. United States, supra. The case holds that the Sixth Amendment rights of a defendant were violated “when there was used against him at his trial evidence of his own incriminating words, which federal agents had deliberately elicited from him after he had been indicted and in the absence of his counsel.” 377 U.S. at 206, 84 S.Ct. 1199.
We have recently had occasion to apply and explain the doctrine of Massiah. In Moore v. United States, 178 F.3d 994 (8th Cir.1999), the defendant Moore claimed that his Sixth Amendment right to counsel had been violated by the use against him at trial of statements he had made that were overheard by a fellow inmate, one Joseph Hartwig. Before he overheard the statements in question, Hartwig had signed an agreement with the government to provide a proffer of information con*921cerning his knowledge of drug-related criminal activity. The charges against Moore were not drug-related, but Hartwig thought that he might benefit from providing information about Moore. He did provide this information, and it was used against Moore at his trial. We held that the testimony was properly admitted. Two elements of the Massiah doctrine were in issue: whether Hartwig was a government agent, and whether he deliberately elicited any information from Moore. Our opinion held against Moore and for the government on both of these points. As to whether Hartwig was a government agent, we stated:
“[A]n informant becomes a government agent for purposes of [Massiah ] only when the informant has been instructed by the police to get information about the particular defendant.” United States v. Birbal, 113 F.3d 342, 346 (2d Cir.1997) (collecting cases). To the extent there was an agreement between Hartwig and the government, there is no evidence to suggest it had anything to do with Moore. The proffer agreement simply evidenced Hartwig’s willingness to disclose his knowledge of drug activity in hopes of receiving a more favorable plea agreement. Even if we were to accept Hartwig’s view that the proffer applied to his knowledge of any illegal activity, there is still no evidence that Hartwig was directed to procure additional information from Moore, or anybody else.
Moore, 178 F.3d at 999.
There is nothing obscure about this language. Quoting the Second Circuit’s opinion in Birbal, we said that an informant becomes a government agent for Massiah purposes only when the informant has been instructed by the police to get information about a particular defendant. (The same position has now been taken by the First Circuit. See United States v. LaBare, 191 F.3d 60, 65 (1st Cir.1999).) As we noted in Moore, the Birbal opinion, the rule of which we adopted, collected cases on the subject. Among these cases were some opinions that took what might be called a broader approach, as opposed to the bright-line, specific language of Bir-bal. We of course were aware of these cases at the time, but nevertheless adopted the Birbal formulation as the rule of this Circuit.
If the Moore opinion is applied as written, Ms. Johnson’s position cannot prevail in the present case. Mr. McNeese was not, at any time before September 11, 2000, instructed, either in express words or by implication, to get information about Ms. Johnson. Mr. McNeese had been helpful to the government in the past. He had proved himself an expert interrogator and informant. We may assume that the government, when Mr. McNeese was placed in the same institution with Ms. Johnson, hoped that Mr. McNeese might come up with something helpful, especially as, at that time, the bodies of the murder victims had not been found. All of these facts, however, when taken together, do not amount to an instruction to Mr. McNeese to get information about Ms. Johnson in particular.
The District Court acknowledged that in “Moore ... the Eighth, Circuit Court of Appeals analyzed the ‘agency’ element of a ‘Massiah violation’ in such a way as to suggest that there is ... a ‘bright line rule’ at least in this circuit .... ” United States v. Johnson, 196 F.Supp.2d at 847. The District Court continued:
Thus, in Moore, the Eighth Circuit Court of Appeals appeared to rely on a sort of “bright line rule” for determination of the agency of an informant, based on whether or not “ ‘the informant has been instructed by the police to get in*922formation about tbe particular defendant.’ ” Id. at 999 (quoting Birbal, 113 F.3d at 346).
196 F.Supp.2d at 848. The District Court then referred to Birbal as “the decision from which the Eighth Circuit Court of Appeals in Moore extracted what appears to be its ‘bright line rule.’ ” 196 F.Supp.2d at 848. The District Court continued: “Moore and Birbal seem to recognize a ‘bright line rule.’ ” 196 F.Supp.2d at 849.
Despite this reading of Moore, with which, incidentally, we agree, the District Court declined to apply the rule of Moore in the present case. Instead, it held that, under all of the facts in the record before it, agency for Massiah purposes was established in the absence of express instructions from the government to get information about a particular defendant “by proof of an implicit agreement arising from a longstanding informant’s ‘roving agency’ or ‘symbiotic relationship’ ” with the government. 196 F.Supp.2d at 857.
The District Court gave two reasons for declining to follow the plain language of Moore. First, the Court observed, and correctly, that the facts in Moore were different. The informant in Moore was not a longstanding cooperator with the government. He had not previously obtained information from a long list of targets of criminal investigations, nor had he previously obtained or been promised benefits in return by government agents. It is certainly true that Moore could have been decided on narrower grounds. We could have pointed out that Hartwig had no extensive history of cooperation with the government in other cases. We did not, however, choose to do so. Instead, we adopted the rule of Birbal, already referred to several times. It will often be possible to reinterpret opinions in past cases and to theorize that they could have been based on narrower grounds. This is not a good enough reason, we think, for disregarding the plain language of such opinions. The Moore Court chose to adopt what the District Court correctly perceived as a bright-line rule. If an informant has not been instructed by the police to get information about the particular defendant, that informant is not a government agent for Massiah purposes. Moore does not say that an informant who has been instructed to get information about a particular defendant is a government agent, but that one may be a government agent in other circumstances, as well. The opinion says that an informant becomes a government agent “only when the informant has been instructed by the police to get information about the particular defendant.” Moore, 178 F.3d at 999. We do not think that this language can be explained away. It is binding on the District Court and on this panel.
Second, the District Court believed that the Moore opinion, if read to state a controlling bright-line rule, would be inconsistent with “the Sixth Amendment principles established in the Supreme Court’s Massiah line of cases .... ” 196 F.Supp.2d at 861. We respectfully disagree with this line of reasoning. Cases like United States v. Henry, 447 U.S. 264, 100 S.Ct. 2183, 65 L.Ed.2d 115 (1980), on which the District Court particularly relied, were decided long before Moore. It must be assumed, and it is in fact true, that this Court was well aware of Henry and other authorities in the Massiah line of Supreme Court cases at the time the Moore opinion was written. Moore, in other words, must be taken as this Court’s authoritative interpretation of those Supreme Court cases. If Henry had been decided after Moore, a different issue would be presented, but that is not the case here. Neither a district court nor a subsequent panel of this Court is free to disregard a previous opin*923ion of this Court on the theory that that earlier opinion was an incorrect interpretation of Supreme Court authority existing at the time. At the time that Moore was decided, it was already clear that some of our sister circuits were using different approaches to resolve the question of agency in Massiah cases. Those courts, presumably, believed that they were acting consistently with Supreme Court precedent. It will frequently happen that different circuits will interpret a line of Supreme Court cases in somewhat different ways. That is what has occurred here. This Circuit’s interpretation is contained in Moore, and we are not free to depart from it.
III.
As we have noted, swpra at 919 n. 2, Ms. Johnson is also the subject of a second indictment, based on the same murders referred to in the first indictment. After fifing its opinion granting Ms. Johnson’s motion to suppress with respect to the first indictment, the District Court filed a second opinion, United States v. Johnson, 225 F.Supp.2d 1022 (N.D.Iowa 2002), holding that the suppression order would apply also to any trial under the second indictment. The Court reached this conclusion on the theory that the second indictment, when closely analyzed, actually charged the same offenses as the first one. The government has also appealed from this holding. In view of our decision that the District Court erred in granting the motion to suppress with respect to the first indictment, we need not separately address any issue of suppression with respect to the second indictment.
IV.
For the reasons given, the order of the District Court, granting Ms. Johnson’s motion to suppress evidence, is reversed. This cause is remanded to the District Court for further proceedings consistent with this opinion.
. A grand jury returned a second indictment against Ms. Johnson on August 30, 2001. That indictment charged her with five counts of committing murders while engaged in a drug-trafficking conspiracy and five counts of committing murders while engaged in a continuing criminal enterprise. 21 U.S.C. § 848(e).