This is an appeal from a conviction for possession and receipt of a firearm, defendant having previously been convicted of a felony, in violation of 18 U.S.C. Â§ 922(h)(1) and 18 U.S.C.App. Â§ 1202(a)(1). The appeal focuses solely on the legality of the seizure at the home of defendant-appellant of the firearm on which the prosecution was based. Appellant attacks the warrant on a number of grounds. Since we find the warrant was invalid because the affidavit failed to supply a sufficient nexus between the firearm and defendant's premises, we treat only this issue. The base point for a determination of whether there was probable cause for issuing a search warrant is Aguilar v. Texas, 378 U.S. 108, 84 S. Ct. 1509, 12 L. Ed. 2d 723 (1964), reaffirmed in Spinelli v. United States, 393 U.S. 410, 89 S. Ct. 584, 21 L. Ed. 2d 637 (1969). There must be a ""substantial basis"" for the magistrate, in this case the Assistant Clerk of the Second District Court of Bristol, Massachusetts, to conclude that evidence of the crime would be found at defendant's home. Aguilar v. Texas, supra, 378 U.S., at 111, 84 S. Ct. 1509 citing Jones v. United States, 362 U.S. 257, 271, 80 S. Ct. 725, 4 L. Ed. 2d 697 (1960). The affidavit must contain facts or circumstances from which the magistrate can make such a determination. Spinelli v. United States, supra, 393 U.S., at 416, 89 S. Ct. 584. Nathanson v. United States, 290 U.S. 41, 47, 54 S. Ct. 11, 78 L. Ed. 159 (1933).