Appeal from the United States District Court for the Northern District of Illinois, Eastern Division. No. 04 CR 243 B-Mark R. Filip, Judge.
The opinion of the court was delivered by: Rovner, Circuit Judge
Before ROVNER, WOOD, and SYKES, Circuit Judges.
Robert Stephenson appeals his sentence for distribution of a controlled substance, objecting to the enhanced penalty he received for distributing crack cocaine. He argues first, that the government failed to prove that he sold crack as opposed to another form of cocaine, second that the enhanced penal-ties for crack cocaine are unconstitutionally vague, and, finally, that the district court had insufficient evidence to include one kilogram of prior crack distribution as relevant conduct. We affirm on each point.
In 2001, the Drug Enforcement Administration (DEA) targeted Stephenson in its ongoing investigation into crack dealing by members of the Gangster Disciples street gang in Evanston, Illinois. As part of the investigation, the DEA employed a confidential source who had negotiated crack deals with persons in the area before, including Stephenson. The confidential source knew Stephenson as a drug seller who dealt exclusively in crack cocaine.
On July 17, 2001, after two phone calls arranging the terms of the transaction, Stephenson and the confidential agent met in a parking lot of an Evanston YMCA where Stephenson sold the confidential source 36.6 grams of a white chunky substance for $1,100. Both the DEA agent and the confidential source visually identified the substance as crack, and field tests confirmed that the powder contained some form of cocaine.
Approximately two weeks later, the confidential source re-contacted Stephenson and, after several phone calls arranging the deal, the two met again. This time, the confidential source purchased a plastic baggie containing 57.7 grams of a hard, brownish tan chunky substance for $1,550. Again, both the DEA agent and the confidential source identified the substance as crack and field tests indicated that the product contained cocaine.
DEA agents arrested Stephenson on November 5, 2001. In a post-arrest interview, after being Mirandized, Stephenson admitted that he was a crack dealer in the Evanston, Illinois area. He revealed that he began pur-chasing small amounts of crack in 1996, and eventually began buying four and five ounce quantities. He estimated that he had purchased one kilogram of crack from one particular seller over the course of a five to six year period, ending in 2003. In a second meeting, again after being Mirandized, Stephenson viewed a tape of the August 2 drug sale and confirmed that he appeared in the video selling crack.
On January 13, 2005, Stephenson entered a blind plea to counts one and two of the superseding indictment which charged him with knowingly and intentionally distributing crack cocaine in violation of 21 U.S.C. § 841(a)(1)-in excess of five grams in count one and fifty grams in count two. After a May 31, 2005 sentencing hearing, on June 2, 2006, the district court sentenced Stephenson to 180 months on counts one and two, to be served concurrently, a fine of $1,000 and a five year term of supervised release for each count.
Stephenson appealed to this court alleging (1) that the government failed to prove by a preponderance of the evidence that Stephenson possessed crack cocaine as opposed to another form of cocaine; (2) that the enhanced penalties for crack cocaine are unconstitutionally vague; and (3) that the district court erred by including one kilogram of prior crack sales as relevant conduct.
Stephenson's primary strategy in this appeal is to cast doubt on the government's evidence that he sold crack as opposed to another form of cocaine. Although recent judicial and congressional actions have lowered some of the sentences for drug crimes involving crack cocaine, sentences for the sale of crack cocaine are still significantly higher than those for other forms of cocaine, and this*fn1 sentence a defendant under the enhanced penalty, the government must prove by a preponderance of the evi- distinction obviously fuels Stephenson's appeal. To dence that the substance at issue is crack, and not some other form of cocaine base. United States v. Branch, 195 F.3d 928, 934 (7th Cir. 1999). As we shall see, more than ample evidence supports the government's contention that Stephenson sold crack cocaine, and we review such a factual determination of the type of drugs involved in an offense for clear error only. United States v. Linton, 235 F.3d 328, 329 (7th Cir. 2000).
Given our sophisticated crime laboratories, it might seem an easy task to determine whether a particular drug is crack or another form of cocaine base, but no chemical test can distinguish between crack and cocaine base. Crack is merely one form of cocaine base-a form that arises as the end result of one method of turning the salt form of cocaine, cocaine hydrochloride (powder cocaine), back into a base form. See United States v. Edwards, 397 F.3d 570, 574 (7th Cir. 2005). Drug dealers alter the form of naturally occurring cocaine to offer drug users their preferred method of ingesting the chemical. Crack can be smoked, but not snorted or injected; powder cocaine can be snorted, but not smoked. Id. at 490-91. Other methods*fn2 of converting cocaine hydrochloride into a base form produce cocaine base that is not crack. See United States v. Booker, 70 F.3d 488, 491 (7th Cir. 1995). For example, freebase cocaine, popular in the 1970s, is another form of cocaine base, although one that has lost popularity due to its volatile and dangerous production methods. Id. This circuit has rejected rigid definitions of crack, noting that to employ such a rigid definition would invite those in the drug trade to make minor changes in structure, processing, or packaging to avoid the increased penalties for selling crack cocaine. United States v. Abdul, 122 F.3d 477, 479 (1997). Instead of applying a rigid definition, this circuit has held that a sentencing judge must determine whether a defendant sold "crack," as those who buy and sell in the market generally understand the term. Id. The experts in this field are those who spend their lives and livelihoods enmeshed with the drugs-users, dealers, and law enforcement officers who specialize in narcotics crimes. United States v. Kelly, 519 F.3d 355, 364 (7th Cir. 2008); United States v. Bradley, 165 F.3d 594, 596 (7th Cir. 1999) ("those who smoke, buy, or sell this stuff are the real experts on what is crack.")
In this case the "experts" all agreed that Stephenson sold crack and not some other form of cocaine to the confidential source. The confidential source, a former crack buyer and addict, readily identified the substance as crack, and also noted that he had never bought any drug other than crack from Stephenson. In fact, the*fn3 confidential source refused the DEA's request that he ask Stephenson for "crack, cooked or hard" because, as the he explained, Stephenson was a crack dealer and only sold crack. Presumably the confidential source was con-cerned that such an obvious reference to crack would blow his cover as a government agent.
The DEA agent who testified at Stephenson's sentencing hearing qualified as another expert in the field. At the time that he testified, DEA Special Agent Steve Moran had worked for the DEA for approximately eight years and had seen hundreds of samples of crack cocaine. See United States v. Gray, 410 F.3d 338, 347 (7th Cir. 2005) (agent who had been with the DEA for seven years and previously had worked for five years as a narcotics canine officer was qualified as expert in ...