In these consolidated appeals, Thomas Ash and Jeffrey Johnson appeal from their convictions for conspiring to attempt to possess with intent to distribute in excess of fifty grams of a substance containing cocaine base, in violation of 21 U.S.C. §§ 841(a)(1), 841 (b)(1)(A)(iii), and 846; attempting to possess with intent to distribute in excess of fifty *762 grams of a substance containing cocaine base, in violation of 21 U.S.C. §§ 841(a)(1), 841(b)(l)(A)(iii), and 846; and using a communication facility in attempting to possess with, intent to distribute in excess of fifty grams of a substance containing cocaine base, in violation of 21 U.S.C. § 843(b). We reject their argument that section 841(b)(l)(A)(iii) is unconstitutional. We find persuasive, however, their argument that evidence obtained following a warrantless entry into a residence should have been' suppressed. Nonetheless, we find that the untainted evidence was so compelling as to render harmless the admission of the illegally-obtained evidence. We also reject the two sentencing challenges raised. Accordingly, we affirm the defendants’ convictions and sentences.
I.
A United States postal inspector in New York received information that a black man wearing a black jacket would mail a package containing crack cocaine to St. Louis from the Uniondale, New York post office. On May 9, 1991, a man fitting this description entered the Uniondale post office and mailed via Express Mail a package addressed to Mrs. Rhymale Buttler, 1 2909 Old Hanley Road, St. Louis, Missouri 63114. The package was removed from the regular mail stream and sent directly to Rod Damery, a postal inspector in St. Louis.
After a narcotics-trained dog indicated that the package contained drugs, Damery applied for and obtained a search warrant for the package. When Damery and another inspector opened the package, they found eighteen plastic bags of cocaine base, or crack, wrapped inside a knit sweater. The package also contained National Supermarket grocery bags and foam as packing material. Planning to execute a controlled delivery, the inspectors removed all but one of the bags and replaced them with a bag of taffy. Additionally, they placed in the package a transmitter, or beeper, which would signal when the package was opened. They then rewrapped the package as it originally appeared.
When a postal inspector dressed as a letter carrier delivered the parcel on May 10, Ash accepted and signed for it, indicating that he was Rhymale Butler. During the delivery, Postal Inspector Ed Moreno was waiting at the federal court' house, where he was to apply for a search warrant as soon as he learned that the parcel had been delivered and taken inside the residence. Within minutes of the delivery and as Moreno was being informed via radio that the package had been accepted, the beeper indicated that the package had been opened. Fearing that evidence would be destroyed, the inspectors decided to enter the residence without waiting for the search warrant to be issued.
Postal Inspector Jerry Post knocked on the door and announced his identity. Receiving no response, he forced the door open. Upon entering the house, he observed the bathroom door closing. He and another officer then forced their way into the bathroom. They observed Johnson attempting to flush the bag of taffy down the toilet and Ash standing in the bathtub. As Johnson flushed the toilet, Post removed the bag from the toilet and threw it on the floor. Post then wrestled with Johnson as he attempted to escape through a window in the bathroom. Johnson was ultimately subdued, and he and Ash were arrested.
The search warrant for the residence was issued some ten minutes after the officers initially entered the house. Postal inspectors then searched the house pursuant to the warrant. In the bedroom where Ash’s girlfriend and child were staying, Inspector Post forrad inside a lock box a small portable scale of thé type commonly used by drug dealers. He also found in a second lock box small baggies used to package cráck and records for a pager in the name of Rhymale Butler. Additionally, Post discovered a piece of paper containing names, dollar amounts, and terms relating to drug quantities. Inspectors recovered the opened package and the sweater in the bathroom, as well as a pager that matched the pager records found in the bedroom. .
*763 At Ash and Johnson’s bench trial, Mr. Kim Smith, a cooperating witness who lived in the residence located at 2909 Old Hanley Road, provided the following testimony. Johnson, who had recently moved from New York, and Ash spent considerable time at the residence. In early May 1991, Smith observed them looking for a box to send money to New York. They found a baby formula box and placed in it a large amount of cash, a sweater of Johnson’s, some National Supermarket grocery bags, and some foam. (At trial, Smith identified the seized box, the foam inside the box, and the recovered sweater as the same items that Ash and Johnson had initially mailed to New York.) Smith drove the two defendants to the United Parcel Service office on Jefferson Avenue in St. Louis, where Ash mailed the package. The next day Smith overheard a telephone conversation in which Ash and Johnson told Johnson’s brother, who lived in New York, that the package was on its way. On May 6, or 7, Smith again observed the defendants placing money in a box so that they could mail it. On May 10, after Ash accepted the parcel from the disguised postal inspector, he and Johnson immediately took it into the bathroom.
Smith’s testimony was corroborated by independent sources. For example, the government- presented UPS records indicating that on May 3, and May 6, 1991, one Rhy-male Butler had sent a package from the UPS office on Jefferson Avenue to Samuel Johnson, 1288 Warwick Street, Uniondale, New York. Additionally, the government offered the testimony of Sharon and Nicole Baird, who in May 1991 lived at 1288 Warwick Street. The Bairds testified that they had rented the lower portion of their home, which is eight-tenths of a mile from the Uniondale post office, to a Samuel Johnson. They recalled that Johnson had received two packages via UPS from St. Louis in early May. Nicole Baird specifically remembered that one of the packages was a brown baby food box.
The district court convicted Ash and Johnson of the three above-described, offenses. The court sentenced Ash to 200 months’ imprisonment, to be followed by five years of supervised release, and Johnson to 228 months’ imprisonment, also to be followed by five years of supervised release.
II.
Ash and Johnson first argue that 21 U.S.C. § 841(b)(l)(A)(iii) is unconstitutional as applied. Section 841(b)(l)(A)(iii) provides that a person convicted of an offense involving more than fifty grams of a substance containing cocaine base shall be sentenced to at least ten years’ imprisonment. Citing evidence that blacks are prosecuted much more frequently than whites for cocaine-base felonies and that the penalties for these offenses are more severe than the penalties for cocaine-powder offenses, Ash and Johnson argue that this section has been applied in a discriminatory manner against blacks, contending that the,. United States Attorney’s Office for the Eastern District of Missouri has employed this section to purposefully discriminate against blacks. They state that since 1988 nearly 100% of cocaine-base prosecutions in the district have been against blacks, whereas 69% of cocaine-powder prosecutions have been against blacks.
In
United States v. Willis,
Additionally, Ash and Johnson argue that the legislative history of section 841(b)(l)(A)(iii) demonstrates that the section is irrational and that Congress had a discriminatory intent in enacting it. We have considered and rejected similar arguments. In
United States v. Buckner,
Ash and Johnson also argue that the guideline ranges for cocaine-base offenses are racially discriminatory. We rejected a similar argument in Lattimore, see id., and so Ash and Johnson’s argument must also fail.
III.
Ash and Johnson next argue that the warrantless entry into the residence violated the Fourth Amendment and that evidence observed following the entry should have been suppressed.
Police officers may not enter or search a home without a warrant, absent exigent circumstances.
See, e.g., Payton v. New York,
The government argues that exigent circumstances existed when the transmitter indicated that the package had been opened. It contends that when the recipient of the package discovered that .the package’s contents had been altered and that the package contained a beeper, the cocaine base was in imminent danger of being destroyed.
• So, far as it goes, the government’s argument is valid. We agree that the ppstal inspectors reasonably believed that evidence was in daqger of being destroyed unless they immediately entered the residence. Nevertheless, in the light of Duchi, we find that the inspectors themselves created that danger.
In
Duchi,
the authorities removed one of two cocaine bricks from a package and replaced it with a book. An officer also initialed the other brick. Shortly after the package was taken into Duchi’s residence, the police entered the house without a warrant because they feared that evidence would be destroyed. The government argued that the officers had properly entered Duchi’s residence without a warrant because the parcel’s altered contents made it likely that the evidence would be destroyed.
Duchi,
• In determining whether the police manufactured the exigent circumstances, we first examined the reasonableness and propriety of the investigative tactics that generated the urgent situation. Id. Employing this standard, we found that the heightened danger that the evidence would be destroyed was the probable result of the officers’ removal and replacement strategy. Id. Because the danger of destruction was created by the officers’ investigative strategy, we found that it could not justify their warrantless entry. Id.
Likewise, we find that the postal inspectors created the exigent circumstances in this ease. As a matter of investigative strategy, *765 they substituted another substance for the cocaine base and placed the beeper in the package. By doing so, the inspectors created, or at least greatly increased, the risk that evidence would be destroyed. Had they not altered the package’s contents, there would have been little or no danger of evidence being destroyed before they obtained the search warrant.
This case is distinguishable from
United States v. Johnson,
Johnson argued that the evidence seized upon entry should have been suppressed, claiming that no exigent circumstances were present to justify the warrantless entry.
Id.
at 445. In rejecting Johnson’s argument, we found that the officers had not manufactured the exigent circumstances justifying the war-rantless entry.
Id.
at 447. We emphasized that obtaining a valid search warrant for the residence would have been very unlikely as a result of the phony name and obscure address on the mailing label.
Id.
The officers did not know whether the address to which they had decided to deliver the package was the intended address. We stated that if the package had been addressed to a real person at a clearly identifiable address, we would have been less disposed to accept the government’s claim of exigent circumstances.
Id.; see also United States v. Templeman,
In contrast to the facts in Johnson, the package in the present case was addressed to a clearly identifiable address, and the inspectors were able to obtain a search warrant shortly after it was delivered. Accordingly, Duchi rather than Johnson controls.
Because the warrantless entry violated the Fourth Amendment, the district court erred in not suppressing all evidence tainted by the illegal entry. From our review of the record, however, it appears that the only tainted evidence admitted at trial was testimony concerning the events that occurred in the bathroom immediately after the officers entered the residence. The untainted evidence against Ash and Johnson was overwhelming, and thus the admission of the tainted testimony was harmless beyond a reasonable doubt.
IV.
We next examine the sentencing issues. Ash and Johnson argue that the district court erred in sentencing them pursuant to 21 U.S.C. § 841(b)(l)(A)(iii), which, as already discussed, provides that a person convicted of a drug offense involving more than fifty grams of a substance containing cocaine base shall be sentenced to a minimum of ten years’ imprisonment. At their sentencing hearing, the defendants argued that the government had failed to establish that the substance mailed to them was cocaine base rather than cocaine powder. The district court rejected their argument.
The district court’s determination that the substance at issue was cocaine base rather than cocaine powder is a finding of fact that we review for clear error.
See, e.g., United States v. Koonce,
Last, Ash argues that the district court erred in assessing him a criminal history point for an adult conviction in Virginia state court for possessing drug paraphernalia. On April 23, 1988, when Ash committed the offense, he was seventeen years old. Possessing the false identification of Jerry Cruz, an adult, Ash pled guilty to the charge as Cruz. On May 12,1988, he was sentenced as an adult, receiving a twelve-month jail sentence, the execution of which was suspended, and two years’ probation. Because he was a juvenile under state law when he committed the crime, Ash now argues that the adult conviction is void as a matter of law and should not have been counted in his criminal history score.
Whether a prior sentence counts for criminal history purposes is a question of federal law, not state law.
United States v. Rayner,
The convictions and sentences are affirmed.
Notes
. Thomas Ash is also known as Rhymale Butler. Butler was spelled with two T’s on the package.
