POLSTER, District Judge, delivered the opinion of the court, in which BATCHELDER, J„ joined. CLAY, J. (pp. 295-800), delivered a separate opinion concurring in part, dissenting in part.
OPINION
POLSTER, District Judge.Defendants Thomas R. Harris and Aaron Taylor appeal from their convictions on *290charges of possession with intent to distribute crack cocaine in violation of 21 U.S.C. § 841(a)(1), claiming that the district court erred in denying their motions to suppress evidence. For the reasons that follow, we AFFIRM the judgments of conviction.
I.BACKGROUND
During the summer of 1998, Detective Stephen Hope of the Chattanooga Police Department (“Chattanooga Police”) learned from a confidential informant that a person known as “Fat Boy” had been selling crack cocaine from a home located at 1241 Poplar Street in Chattanooga, Tennessee (“the residence”). On August 11, 1998, Detective Hope sent the confidential informant to the residence to make a controlled purchase. The confidential informant purchased one “rock” of crack cocaine from “Fat Boy” on that day. On October 8, 1998, the confidential informant returned to the residence and purchased another “rock” of crack cocaine.
On October 9, 1998, Detective Hope prepared an affidavit containing the following information and presented it to a state court judge:
I, Stephen L. Hope, hereby apply for a search warrant and make oath as follows:
1. I am a sworn Chattanooga Police Officer with the Narcotics Division, where I have been assigned to the Narcotics Division since 1996.
2. That on the [sic] 10-8-98, I received reliable information from an informant I have known for the last five months.
3. The said informant has proven to be reliable after the information said informant provided was independently corroborated by Detective Hope.
4. The said informant has provided information in the past that has lead [sic] to the arrest and conviction of individuals in violation of narcotic laws.
5. The said informant has provided information to other law enforcement officers in the past that has proven to be true and correct when independently corroborated by those other law enforcement officers.
6. The said informant has made several controlled narcotic buys for me in the last five months.
7. That said informant advised me that within the last 72 hours said informant was on the premises of said John Doe (alias), who resides in or occupies and is in possession of the following described premises, to wit; 1241 Poplar Street Court, Chattanooga, Hamilton County, Tennessee., [sic] While there said informant saw legend and/or narcotic drugs including Crack Cocaine, the same being on said premises in the possession of and control of said John Doe (alias).
Wherefore, as such officer acting in performance of my duty in the premises I pray that the Court issue a warrant authorizing the search of the said John Doe (alias) and the premises herein described for said legend and/or narcotic drugs including Crack Cocaine and that such search be made either by day or night.
In addition to filing the affidavit, Detective Hope orally advised the state court judge of the name and identity of the confidential informant and of the fact that the confidential informant had made two controlled buys at the residence. The state court judge issued the search warrant based upon the information presented to him. Later the same day, October 9, 1998, Detective Hope sent the confidential informant back to the residence to attempt another controlled buy. The confidential *291informant found “Fat Boy” at the residence, but was not successful in purchasing crack cocaine. The Chattanooga Police waited until the next week to execute the search warrant because the confidential informant told Detective Hope that drugs might not be found at the 1241 Poplar Street address over the weekend.
On October 13, 1998, the Chattanooga Police executed the search warrant that had been issued four days earlier. When they arrived at the residence, the police officers knocked on the front door and announced their presence. After receiving no response, the officers entered the residence. Officers caught Defendant Taylor attempting to flee the residence while carrying crack cocaine on his person. A detective found Defendant Harris in a second-floor bathroom, seated on a toilet with' a pile of crack cocaine located next to him. The detective did not knock before entering the bathroom, but had shouted, “Police, warrant!” as he proceeded up the stairs to the second floor.
Both defendants filed motions to suppress evidence obtained by police during the search. Taylor’s motion to suppress argued that the affidavit in support of the search warrant did not establish probable cause and that the good faith exception to the exclusionary rule should not apply because the officer knew or should have known that he did not have probable cause. Harris’ motion to suppress argued, that the evidence found in the bathroom should be suppressed because the detective violated Harris’ legitimate expectation of privacy by entering the bathroom while he was seated on the toilet without first knocking on the closed door and announcing the purpose of entry. Although Harris did not raise lack of probable cause for the search in his motion to suppress, he subsequently joined in the motion filed by Taylor.
Following a joint evidentiary hearing, the trial court denied Taylor’s motion to suppress. Although the court found that the detective’s affidavit “f[ell] a little short of establishing probable cause under the Fourth Amendment,” it concluded that the search fell within the good faith exception to the exclusionary rule set forth in United States v. Leon, 468 U.S. 897, 104 S.Ct. 3405, 82 L.Ed.2d 677 (1984). The court also denied Harris’ motion to suppress. The court’s denial of that motion rested upon its. finding that Harris possessed no legitimate expectation of privacy in the bathroom because he was merely a temporary visitor present in the house for the purpose of purchasing or trafficking in crack cocaine.
On August 16, 1999, Taylor and Harris entered conditional guilty pleas, admitting the factual basis for their convictions, but reserving the right to challenge the district court’s denial of their motions to suppress. On appeal, both defendants contend that the district court erred in finding that the Leon exception applied. Harris further contends that the trial court erred in finding that he had no legitimate expectation of privacy while using a toilet in the bathroom of the residence.
II. DISCUSSION
A. Standard of Review
A district court’s ruling on a motion to suppress is subject to a mixed standard of review. The factual findings supporting the court’s decision must be accepted unless they are clearly erroneous. United States v. King, 227 F.3d 732, 739 (6th Cir.2000). The court’s final determination as to the reasonableness of the search is, however, a question of law that must be reviewed de novo. Knox County Education Ass’n v. Knox County Board of Education, 158 F.3d 361, 371 (6th Cir. *2921998). When reviewing the district court’s denial of a motion to suppress, we consider the evidence in the light most favorable to the government. United States v. Garza, 10 F.3d 1241, 1245 (6th Cir.1993).
B. The Search Warrant
The Fourth Amendment provides that “no Warrants shall issue, but upon probable cause supported by Oath or affirmation.... ” U.S. Const. Amend. IV. This Court has defined probable cause as “reasonable grounds for belief, supported by less than prima facie proof but more than mere suspicion.” United States v. Bennett, 905 F.2d 931, 934 (6th Cir.1990). A finding of probable cause does not require an actual showing of criminal activity, but rather, “requires ‘only a probability or substantial chance of criminal activity....’ ” United States v. Smith, 182 F.3d 473, 477 (quoting Illinois v. Gates, 462 U.S. 213, 244, n. 13, 103 S.Ct. 2317, 76 L.Ed.2d 527 (1983)).
In this case, the district court held that the affidavit provided by Detective Hope to the state court judge did not provide a sufficient basis for establishing probable cause for the search. It reached this conclusion after reviewing the decision in United States v. Allen, 168 F.3d 293 (6th Cir.1999), which concerned the issuance of a search warrant based upon an affidavit quite similar to the one in this case. The affidavit in Allen, prepared by an officer from the same police department as Detective Hope, stated that the officer had learned from a confidential source that a person residing at a certain house was in possession of cocaine. Id. at 296. The officer noted in the affidavit that the informant had previously provided him with reliable information about individuals engaged in criminal activities and that he had known the informant for five years. Id. During a hearing on the warrant, the officer disclosed the name of the informant to the magistrate. Id. at 297. The panel in Allen determined that the warrant failed to establish probable cause.
During the pendency of this appeal, this Court, sitting en banc, reversed the panel decision in Allen relied upon by the district court. 211 F.3d 970 (6th Cir.), cert, denied, 531 U.S. 907, 121 S.Ct. 251, 148 L.Ed.2d 181 (2000). In the en banc decision, we held that “where a known person, named to the magistrate, to whose reliability an officer attests with some detail, states that he has seen a particular crime and particular evidence, in the recent past, a neutral and detached magistrate may believe that evidence of a crime will be found.” Id. at 976.
In the case at hand, Detective Hope provided the state court judge with an affidavit stating that he had known the confidential informant for five months, the informant had made several controlled narcotics buys for him during that time, and that the informant had provided reliable information in the past to him and others in the department. The affidavit further recited that the informant had provided information that led to the prosecution and conviction of individuals for violation of narcotics laws. Accordingly, the affidavit in this case provided more detail evidencing probable cause than the Allen affidavit, which recited the informant’s value in prosecuting individuals charged in “criminal activity,” and which did not recite that the informant had made recent undercover drug purchases.
When he appeared before the state court judge, Detective Hope revealed the confidential informant’s identity and orally advised the judge that the informant had *293made two controlled purchases of crack cocaine from the residence.1 Under the standard articulated in the en banc Allen decision, the affidavit in this case coupled with the detective’s sworn testimony provided a sufficient basis for the state court judge to find, based upon the totality of the circumstances, that there was probable cause for the search. Accordingly, the defendants’ motions to suppress were properly denied. United States v. Garza, 10 F.3d 1241, 1245 (6th Cir.1993) (“A district court’s ‘denial of a motion to suppress will be affirmed on appeal if proper for any reasonf,]’ even one not relied upon by the court.”) (quoting United States v. Barrett, 890 F.2d 855, 860 (6th Cir.1989) (superseded by statute)).
Moreover, even if there was not probable cause for the issuance of the warrant, the fruits of the search would have been admissible under United States v. Leon, 468 U.S. 897, 104 S.Ct. 3405, 82 L.Ed.2d 677 (1984). In Leon, the United States Supreme Court held that the Fourth Amendment exclusionary rule should not be used to bar the use of evidence obtained by officers acting in reasonable reliance on a search warrant issued by a neutral and detached magistrate that is later found to be invalid. Id. The Supreme Court provided the following guideline for determining whether evidence seized through an invalid warrant should be excluded:
In the absence of an allegation that the magistrate abandoned his detached and neutral role, suppression is appropriate only if the officers were dishonest or reckless in preparing their affidavit or could not have harbored an objectively reasonable belief in the existence of probable cause.
Id. at 926,104 S.Ct. 3405.
In this case, there is no evidence that the state court judge abandoned his detached or neutral role or that Detective Hope was dishonest or reckless in preparing the affidavit. Nor is there reason to believe that a reasonably well trained police officer would not have believed that there was probable cause to search the home. Detective Hope received information about drug-related activities at 1241 Poplar Street from a confidential informant he had known for five months and who had provided reliable information in the past. Unlike the officer in Allen, Detective Hope corroborated the informant’s tip prior to seeking a warrant by arranging for two controlled purchases from the address. Detective Hope included most of this information in his affidavit and provided additional sworn testimony at the hearing on the warrant. Under these circumstances, a reasonable police officer, even one who was operating under the since vacated Allen decision, would have concluded that there was probable cause to search the residence.
On appeal, Defendant Taylor argues that a reasonable officer would no longer have believed that there was probable cause for the search because the confidential informant failed to purchase drugs at the residence on the day the warrant was issued and officers waited four days before executing the warrant. This argument was not raised below, and is therefore waived. See, e.g., J.C. Wyckoff & Associates, Inc. v. Standard Fire Ins. Co., 936 F.2d 1474, 1488 (6th Cir.1991) (“Issues not presented to the district court but raised for the first time on appeal are not *294properly before the court”)- In any event, the inability of the confidential informant to make a third controlled purchase of crack cocaine and the four-day delay in the execution of the warrant are of little consequence given the prior controlled drug purchases and the continuing presence of “Fat Boy” at the residence. See, e.g., United States v. Word, 806 F.2d 658, 662 (6th Cir.1986) (probable cause for search existed despite passage of four months since last documented drug sale and twenty-nine day gap between last suspicious event recounted in affidavit and execution of search warrant); United States v. Spikes, 158 F.3d 913, 923 (6th Cir.1998), cert, denied, 525 U.S. 1086, 119 S.Ct. 836, 142 L.Ed.2d 692 (1999) (trial court properly denied motion to suppress even though some of the events included in the affidavit occurred four years ago and officer did not apply for warrant until ten days after discovery of drug trafficking paraphernalia in trash of residence); United States v. Fisher, 137 F.3d 1158, 1164 (9th Cir.1998) (“[E]vidence of a criminal business operating at a particular location in the not-so-distant past may reasonably give rise to a belief that a search of the location would yield further evidence.”).
This case is no different than it would have been had Officer Hope sent the informant into the residence at 1241 Poplar Street on three occasions prior to applying for the search warrant and the informant had been successful in purchasing drugs on only two of the occasions. Probable cause is not defeated simply because an informant was unable to purchase drugs on one occasion prior to the execution of the search warrant. See, e.g., United States v. Charles, 138 F.3d 257, 263 (6th Cir.1998) (omission from search warrant affidavit that law enforcement officer made several unsuccessful attempts to purchase drugs from subject does not make the affidavit false or defeat probable cause); United States v. Sugar, 606 F.Supp. 1134, 1150-51 (S.D.N.Y.1985) (probable cause not vitiated by failure of officer to inform magistrate that undercover agent had been unsuccessful in attempt to obtain drug from defendants). It is not as if the informant reported to Officer Hope that “Fat Boy” no longer lived at 1241 Poplar Street, or that the drug operation had ceased. The informant simply told Officer Hope that drugs might not be found over the weekend.
For the above reasons, we hold that there was probable cause for the issuance of the search warrant, and further, that the district court did not err in finding that the Leon exception would apply even in the absence of a warrant founded on probable cause.
C. Expectation of Privacy in Bathroom
Defendant Harris has conceded that he was merely a casual (non-overnight) visitor at 1241 Poplar Street when the search was executed. Accordingly, his only basis for suppressing the fruits of the search is his claim that he had a legitimate expectation of privacy while using the bathroom during the search, a contention rejected by the district court.
A person who claims that his Fourth Amendment rights were violated by an unreasonable search must establish that he or she had a subjective expectation of privacy in the premises searched and that society would recognize his or her expectation as legitimate. Minnesota v. Carter, 525 U.S. 83, 119 S.Ct. 469, 472, 142 L.Ed.2d 373 (1998). In determining whether an individual has a legitimate expectation of privacy, we look to the nature of the individual’s ties to the property. Id. at 473. Although an overnight guest may possess a legitimate expectation of privacy *295in a residence being searched, a temporary visitor to a residence may claim no such protection. Id. This is particularly true where, as here, the person seeking the protections of the Fourth Amendment was on the premises for the sole purpose of engaging in drug-related business transactions. Id.
Harris attempts to circumvent the difficulties of establishing that he had a legitimate expectation of privacy in the residence by focusing on the fact that he was using a bathroom at the time of the raid. Citing United States v. Delaney, 52 F.3d 182 (8th Cir.1995) and Kroehler v. Scott, 391 F.Supp. 1114 (E.D.Pa.1975), Harris contends that he possessed an objectively reasonable expectation of privacy because he was using the bathroom of the residence and that as a result, police should have knocked on the door of the bathroom before entering. The cases cited by Harris offer little support for his position.
In Delaney, the Eighth Circuit Court of Appeals recognized that an occupant of a stall in a public restroom may have a reasonable expectation of privacy against clandestine police surveillance, but rejected the privacy claim of a defendant who police observed in a restroom stall during the course of “a lawful investigative stop.” 52 F.3d at 188. Kroehler stands for essentially the same proposition recognized by the court in Delaney — an individual who is using a public restroom has a privacy interest in being free of police surveillance conducted without a warrant or probable cause that would justify a warrant. 391 F.Supp. 1114. Neither case even remotely suggests that officers executing a search warrant should knock and announce their presence before opening an interior door behind which there may be a bathroom.
In this case, police were not engaging in clandestine surveillance of a public restroom, but instead were executing a search warrant at a private residence known as a center of drug trafficking activity. Extending the “knock and announce” rule to any interior door that might have a bathroom behind it would far exceed the requirements of the Fourth Amendment and would substantially hinder law enforcement efforts. See, e.g., United States v. Spikes, 158 F.3d 913, 926 (6th Cir.1998) (officers who entered home 15 to 30 seconds after knocking and announcing their presence did not violate Fourth Amendment where additional delay may have enabled drug traffickers to destroy evidence and take additional steps to defend themselves and their drugs). The bathroom is the obvious place to retreat in order to flush drugs or other contraband down the toilet, and it would be absurd to require law enforcement officers searching a residence for drugs to delay searching a bathroom that they could tell was occupied. Accordingly, we hold that the district court did not err in concluding that Harris possessed no legitimate expectation of privacy in the bathroom of the residence.
III. CONCLUSION
For the reasons stated above, we AFFIRM the district court’s denial of the defendants’ motions to suppress.
. Detective Hope testified at the suppression hearing that when he appeared before the state judge on October 9, 1998, to apply for the search warrant, the state judge put Hope under oath.