The question submitted has given the court some difficulty. Certain propositions and principles will aid in its correct decision:
1. Statutes creating crimes will not be extended by judicial interpretation to cases not plainly and unmistakably within their terms. If this rule is lost sight of, the courts may hold an act to be a crime when the legislature never so intended. If there is a fair doubt whether the act charged in the indictment is embraced in the criminal prohibition, that doubt is to be resolved in favor of the accused. U. S. v. Morris, 14 Pet [39 U. S.] 694; U. S. v. Wiltberger, 5 Wheat. [18 U. S.] 76; U. S. v. Sheldon, 2 Wheat [15 U. S.] 119; U. S. v. Clayton [Case No. 14,814].
2. Congress has, it is conceded, no power to make criminal the using of means to prevent conception, or • to procure abortion, etc., in the several states. That power belongs to the respective states. But- congress has plenary power over the mails and postal service, and may, undoubtedly, declare what shall not be mailable matter, and punish violation of its criminal enactments in this regard. The protection of the public morals in such cases is incidental to the protection of the mails. U. S. v. Bott [Case No. 14,626]; In re Jackson [96 U. S. 727], Oct. term, 1877. The statute upon which this indictment is founded must be construed with reference to this limitation upon the federal function and the supposed federal purpose in the enactment of the statute. Congress meant by this legislation to prevent the mails from being used to transport matter corrupting to the public morals. Re Jackson, supra. •
3. Where persons are suspected of. being engaged in the violation of criminal laws, or of intending to commit an offence, it is allowable to resort to detective measures to procure evidence of such fact or intention. Many frauds upon the postal, revenue, and other laws are of such a secret nature that they can be effectually discovered in no other way. Accordingly, there have been numerous convictions upon evidence procured by means of what are called “decoy letters”—that is, letters prepared and mailed on purpose to detect the offender—and it is no objection to the conviction, when the prohibited act has been done, that it was discovered by means of letters specially prepared and mailed by the officers of the government, and addressed to a person who had no actual existence. The books contain many eases where such convictions have been sustained. U. S. v. Cottingham [Case No. 14,872]; Reg. v. Rathbone, 2 Moody, Crown Cas. 310, Car. & M. 220; Reg. v. Gardner, 1 Car. & K. 628; Reg. v. Williams, Id. 195; Reg. v. Mence, 1 Car. & M. 234.
There is á class of eases in respect of larceny and robbery in which it is held that *593where one person procures, or originally induces, the commission o£ the act by another, the person who does the act cannot be convicted of these particular crimes, although he supposed he was taking the property without the consent, or against the will, of the owner. Archb. Cr. Prac. & Ev. 364; Rex v. Eggington, 2 Bos. & P. 508; State v. Covington, 2 Bailey, 569; Dodge v. Brittain, Meigs, 84, 86; Alexander v. State, 12 Tex. 540; 3 Chit. Cr. Law, 925; 2 East, P. C. 665; 1 Bish. Cr. Law (5th Ed.) §§ 262, 263. The reason is obvious, viz.: The taking in such cases is not against the will of the owner, which is the very essence of the offence, and hence no offence, in the eye of the law, has been committed. The offender may be as morally guilty as if the owner had not consented, but a necessary ingredient of legal guilt is wanting. This is strikingly shown by Rex v. McDaniel, Fost. Crown Law, 121, 2 East, P. C. 665, where “Salmon, McDaniel, and others conspired to procure two persons, ignorant of the design, to rob Salmon on the highway; in order that they might obtain the reward at that time given for prosecuting offenders for highway robbery. Salmon, accordingly, went to the particular place fixed upon, with some money, and the two men who were procured, being led there by one of the conspirators, robbed him, and they were afterwards prosecuted and convicted; but the conspiracy being afterwards detected, the conspirators were indicted as accessories before the fact to the robbery, and, the facts being found by a special verdict, the case was argued before all the judges, who held that the taking of Salmon’s money was not a larceny, being done not only with his consent, but by his procurement.” But this principle must be limited to the eases where the consent will, as a matter of law, neutralize the otherwise criminal quality of the act. 1 Bish. Cr. Law (5th Ed.) § 262. Thus, where a prosecution was founded on an act of the legislature imposing a penalty on any one who should deal or trafile with a slave without a written ticket or permit from the owner, it is held that the of-fence is consummated, although the trading was done by the slave in pursuance of instructions of the owner, and in his presence, when the accused was ignorant of such instructions and presence. The reason is that, “like Eggington’s Case,- supra, this is a contrivance to detect the offender.” State v. Covington, 2 Bailey, 569, 573. See. also, Reg. v. Williams, 1 Car. & K. 195; Reg. v. Gardner, Id. 628.
The facts in the case now under consideration show that the defendant is as morally guilty as if the letter he was answering had been written by a person seeking the prohibited information, and not by a detective. But I am of the opinion that these facts do not clearly bring the case within the particular clause of the statute on which the indictment is founded. The indictment charges that the defendant knowingly deposited in the mail a letter giving information where, how, and of whom an article or thing designed and intended to prevent conception could be procured. This was in answer to a fictitious letter of inquiry. The letter written and mailed by defendant was addressed to a person who had no existence. On its face it did not show that it was within the prohibited statute. If it had been suffered to go through the mail to the place to which it was addressed, it would not have been called for, but would have been sent to the dead-letter office, and could not have given to any person the prohibited information. The defendant doubtless intended to give the inhibited information, but the statute does not apply to a letter merely intended by the writer to give such information, but to a letter “ ‘actually’ giving the information.” If a letter of inquiry seeking the prohibited information had been written by an actual person, although under ■a feigned name, an answer in reply, giving such information, would present a case distinguishable, it would seem, from the one under consideration.
I place my judgment in this case upon the single ground that the sealed letter written by the defendant, addressed to a person who had no existence, and which on its face gave no information of the prohibited character, and which is brought within the statute only by the fictitious letter of inquiry written by a detective, is not the “giving of information” within the meaning of the statute. At all events, it is not certain that congress intended to punish such an act; and, therefore, upon the principle above mentioned, that criminal statutes are not to be extended by judicial construction to cases not clearly and. unmistakably within their terms, my judgment is that this prosecution, on the admitted facts, cannot be sustained. It is a case of clear moral guilt, but not of legal criminality. There is no legal crime committed, although the defendant did not know of the fact which deprived his act of its criminal quality. 1 Bish. Cr. Law (5th Ed.) § 262. In this respect the case falls within the principle strikingly illustrated by Rex v. McDaniel, above referred, to.
• In order to prevent misconception of the decision now made, it may be proper to add that we only decide the narrow and single point that the letter written and deposited by the defendant did not give the prohibited information, and hence is not within the statute. It would present a different case for consideration if the letter written and deposited by the defendant had been capable, into whosesoever hands it might have fallen or come, of imparting the prohibited information.
We do not decide that decoy letters cannot be used to detect persons engaged, or suspected to be engaged, in violating criminal laws, but recognize the doctrine that such letters may be so used. We only decide that the defendant, by his answer to the decoy letter, did not, .under the special circumstan*594ces of the ease, bring himself within the criminal prohibition of the act of congress.
It would also present a different case if the letter of inquiry had been written by some person actually seeking the prohibited information for immoral purposes, although written under an a,sumed name, and the defendant had mailed such a letter as he actually wrote and deposited in this case. Congress has not, and probably cannot, make the business in which it is claimed the defendant is engaged, viz., of furnishing to whoever may apply therefor the means of preventing conception, to procure abortion, etc., illegal, and punish the same; but the state of Missouri may do so. If the state has done so, and the defendant is suspected of being engaged in the illegal business, undoubtedly decoy letters may be used for the purpose of discovering his violation of the law, as the cases above cited show. And if, in answer to a decoy letter, the prisoner deposits in the mail any written or printed card, circular, etc., which on its face gives information of the prohibited character, there is nothing in this decision which precludes us from holding such a case, if it should arise, to be within the act of congress.
On the admitted facts, I am of opinion, for the reasons above given, that the prosecution cannot be maintained.