Tamara Joy Hopwood, Respondent, vs. City of St. Paul, Appellant.

may not be cited except as provided by

Minn. Stat. § 480 A. 08, subd. 3 (1998).

 STATE OF MINNESOTA

 IN COURT OF APPEALS

 C1-98-2049

 C7-98-1942

Tamara Joy Hopwood,

Respondent,

vs.

City of St. Paul,

Appellant.

 Filed June 22, 1999

 Affirmed

 Schultz, Judge[*]

Ramsey County District Court

File No. C1954896

David O'Connor, Kathleen O'Connor, 386 North Wabasha Street, 1500 Capital Centre, St. Paul, MN 55102 (for respondent)

Clayton M. Robinson, Jr., St. Paul City Attorney, James F.X. Jerskey, Assistant City Attorney, 550 City Hall, 15 West Kellogg Blvd., St. Paul, MN 55102 (for appellant)

Considered and decided by Short, Presiding Judge, Peterson, Judge, and Schultz, Judge.

 U N P U B L I S H E D O P I N I O N

 SCHULTZ, Judge

Appellant City of St. Paul challenges the district court's verdict in favor of respondent Tamara Hopwood on her claim of reprisal. The city argues that Hopwood failed to establish the elements of a reprisal claim, the district court failed to properly apply the McDonnell Douglas burden-shifting analysis to Hopwood's claim, the district court's admission of testimony from Hopwood's expert witness was an abuse of discretion, and the district court erroneously awarded attorney fees and expert witness fees. On appeal, Hopwood argues that the post-trial judge's award of fees and the post-trial judge's failure to remove himself were erroneous. We affirm.

 FACTS

In 1991, the St. Paul Police Department hired Hopwood. On December 13, 1992, while assigned to the city's southwest sector, Hopwood went to a bar in St. Paul. That evening, Hopwood allowed a male friend to sit in her car as they waited for his car to warm up. As Hopwood and her friend were waiting, a St. Paul police squad car approached Hopwood's car and shined a light on her vehicle. The officers in the squad car, Mike Bratsch and Mike Wright, saw her, waved and continued down the street. According to Hopwood, she has never had a romantic relationship with her friend and did not have a sexual encounter with him while sitting in her car.

When Hopwood returned to work two days later, Officer Sue Drutschmann informed Hopwood that some officers were saying that she had been performing oral sex on her male friend while they sat in her vehicle near the bar. After hearing the rumors, Hopwood told Officer Bratsch to stop spreading the rumors about her sexual activity. According to Hopwood, Bratsch told her that "he told a few of the guys at breakfast that morning, and that he didn't think that it would get so out of hand." Later, Hopwood began to hear "sucking noises" over the air as she spoke with officers on the radio or received radio transmissions. Hopwood again confronted Bratsch, as well as Officer Mike Findley, and instructed them to cease the behavior.

On January 5, 1993, after speaking with fellow officers and St. Paul Chief of Police William Finney, Hopwood filed a complaint with the police department's internal affairs unit and the city's human resources department alleging sexual harassment by her fellow officers. Sergeant Robert Weston and Commander Ted Brown investigated the complaint. After interviewing seventeen individuals, the internal affairs unit was unable to determine who made the sucking sounds.

A series of retaliatory acts by some of Hopwood's coworkers followed the filing of the complaint. For example, some of Hopwood's fellow patrol officers shunned her by refusing to socialize and communicate with her after she filed the complaint. Additionally, Officers Mike Findley and Mike Reuvers approached Hopwood in a St. Paul restaurant while she was on duty and told her that "nobody wants you in here. Everybody's pissed off at you because of the complaint." After Hopwood filed the sexual harassment complaint, Officer Thomas Arnold sent a letter to Chief Finney alleging that Hopwood was a drug dealer's girlfriend, that she accepted drug money, and that she informed suspected drug dealers of impending raids. As a result of the letter, Chief Finney ordered an extensive investigation that did not verify any of the allegations.

Hopwood's fellow officers engaged in other retaliatory acts after she filed the sexual harassment claim. When Hopwood was assigned to the east sector, an officer improperly removed some of Hopwood's incident reports from the report bin. Additionally, after Hopwood was placed on reduced status, a ranking officer announced at roll call that Hopwood had been "sent back to the Academy," a comment that evoked laughter. On at least one occasion after Hopwood filed her sexual harassment complaint, she did not receive back-up from other officers when those officers were available.

Based on these facts, Hopwood filed a complaint alleging sexual harassment, reprisal, intentional infliction of emotional distress, and negligent supervision. On summary judgment, the district court dismissed Hopwood's sexual harassment, intentional infliction of emotional distress and negligent supervision claims. The reprisal claim was tried in a court trial in April 1998. The district court found in favor of Hopwood and awarded $55,000 for compensatory and punitive damages.

 D E C I S I O N

 I.

The city contends that the district court erroneously concluded that Hopwood suffered an adverse employment action and that the adverse employment action was causally connected to her sexual harassment claim. In all actions tried on the facts without a jury, the district court's findings of fact shall not be set aside unless clearly erroneous, giving due regard to the district court to judge the credibility of witnesses. Minn. R. Civ. P. 52.01. A district court's findings of fact will be reversed only if the reviewing court is left with a definite and firm conviction that a mistake has been made. Gjovik v. Strope, 401 N.W.2d 664, 667 (Minn. 1987) (citations omitted).

Minn. Stat. § 363.03, subd. 7(1) prohibits an employer from intentionally engaging in reprisal against an employee because that employee

[o]pposed a practice forbidden under this chapter or has filed a charge, testified, assisted, or participated in any manner in an investigation, proceeding, or hearing under this chapter.

Minn. Stat. § 363.03, subd. 7(1) (1996). To establish a prima facie case of reprisal, an employee must establish 1) statutorily protected conduct; 2) adverse employment action; and 3) a causal connection between the protected conduct and the adverse action. Hubbard v. United Press Int'l, 330 N.W.2d 428, 444 (Minn. 1983). After establishing the prima facie case, the burden of production shifts to the employer to present evidence of legitimate, non-discriminatory reasons for its actions. Sigurdson v. Isanti County, 386 N.W.2d 715, 720 (Minn. 1986) (Sigurdson I) (citing Texas Dep't of Community Affairs v. Burdine, 450 U.S. 248, 254, 101 S. Ct. 1089, 1094 (1981)). If the employer carries its burden of production, the plaintiff has the burden of persuading the district court by a preponderance of the evidence that the employer engaged in reprisal. Id. At all times, the burden of persuasion is on the plaintiff. Id. at 720 n.2.

Adverse employment actions include intimidation, retaliation, harassment, or departure from customary employment practice. Minn. Stat. § 363.03, subd. 7(2). The Minnesota Human Rights Act "does not impose a duty on the employer to maintain a pristine working environment." Continental Can Co., Inc. v. State by Wilson, 297 N.W.2d 241, 249 (Minn. 1980). However, "an employer must act to prevent and correct harassment when it becomes aware of the problem." McNabb v. Cub Foods, 352 N.W.2d 378, 384 (Minn. 1984) (citing Fekete v. United States Steel Corp., 353 F. Supp. 1177, 1186 (W.D. Pa. 1973)).

In this case, the city does not contest that Hopwood engaged in statutorily protected activity, but does argue that the district court clearly erred in finding an adverse employment action and a causal connection. The district court's factual findings that established an adverse employment action are well supported by the record. The trial testimony received by the district court established that Hopwood was confronted with many forms of harassing and retaliatory conduct. Although Hopwood's supervising officers did not engage in the harassing and intimidating conduct, the district court found that their failure to discipline Hopwood's fellow officers led to the harassing behavior. This finding was based on the expert testimony of Anthony Bouza who stated that the police department's failure to vigorously investigate Hopwood's sexual harassment claim "demonstrates * * * a tacit toleration and unconscious encouragement of such behavior." See McNabb, 352 N.W.2d at 384 (holding that "[t]he failure of management to timely discipline employees is strong evidence of acquiescence of discriminatory practices by subordinates"). The record and the relevant legal authorities support the district court's implicit conclusion that Hopwood suffered an adverse employment action.

The causal connection between protected activity and an adverse employment action may be satisfied "by evidence of circumstances that justify an inference of retaliatory motive, such as a showing that the employer has actual or imputed knowledge of the protected activity and the adverse employment action follows closely in time." Hubbard, 330 N.W.2d at 445. The record supports the district court's finding that Hopwood established a causal connection between her protected activity and the adverse employment action. For example, Officer Reuvers told Hopwood that, "Everybody's pissed off at you because of the complaint." Moreover, the timing of the harassing treatment suggests that it resulted from Hopwood's filing of the sexual harassment complaint. Before she filed the complaint, Hopwood had a good relationship with her fellow officers. After she filed the complaint, Hopwood failed to receive proper backup and was subjected to other forms of hostile treatment by her fellow officers. For these reasons, the record supports the district court's finding that Hopwood established a prima facie case of reprisal.

After Hopwood established her prima facie case, the burden of production shifted to the city to present evidence of some legitimate reason for its actions. Sigurdson v. Isanti County, 408 N.W.2d 654, 657 (Minn. App. 1987), review denied (Minn. Aug. 19, 1987) (Sigurdson II). In assessing the employer's evidence, a district court should look for evidence that the employer's actions were related to some legitimate business purpose. Sigurdson I, 386 N.W.2d at 720 (citing Furnco Constr. Corp. v. Waters, 438 U.S. 567, 577, 98 S. Ct. 2943, 2949 (1978)).

The city contends that the harassing conduct resulted from Hopwood's inadequacies as an officer. In addition, the city cites Hopwood's acknowledged social relationship with a suspected drug dealer as a basis for the harassing conduct. Although some of the retaliation may have been a result of Hopwood's poor safety record, the record clearly supports a finding that Hopwood's fellow officers acted in retaliation for her filing the sexual harassment complaint. For example, Hopwood was expressly told that the officers were angry with her because she filed the complaint. Additionally, the record does not support a finding that officers failed to back up a fellow officer during a felony call merely because she tended to position her squad car poorly. Finally, none of the city's proffered reasons address the supervising officers' failure to adequately discipline Hopwood's fellow officers.

For all of the foregoing reasons, the city did not meet its burden of production by showing that its actions were related to a legitimate purpose. Sigurdson I, 386 N.W.2d at 720. Even if the city met its burden of production, the record indicates that its proffered explanations are "unworthy of credence." Id. (citation omitted).

 II.

The city also contends that the district court's failure to correctly employ the McDonnell Douglas test when considering Hopwood's reprisal claim requires reversal. A reviewing court is not bound by and need not give deference to a district court's decision on a purely legal issue. Frost-Benco Elec. Ass'n v. Minnesota Pub. Utils. Comm'n, 358 N.W.2d 639, 642 (Minn. 1984).

Reprisal claims are analyzed under the McDonnell Douglas burden-shifting scheme. Hubbard, 330 N.W.2d at 444. In Sigurdson I, the supreme court indicated that district courts must explicitly employ the burden-shifting analysis. 386 N.W.2d at 722. However, the supreme court has not stated that district courts must "rigidly and mechanically apply" the test. Id. at 721. Rather, the test is merely a tool to be used to evaluate evidence. Id. at 722.

In its written findings, the district court did not explicitly apply the McDonnell Douglas burden-shifting analysis. However, this deficiency does not require reversal. The supreme court has stated that the explicit use of the McDonnell Douglas analysis is crucial because a failure to explicitly employ the analysis greatly limits a reviewing court's ability to assess the district court's conclusions of law. Id. As the preceding analysis indicates, the district court's failure to use the McDonnell Douglas analysis did not limit our ability to evaluate the district court's conclusions. Under these circumstances, the district court's failure to explicitly apply the McDonnell Douglas analysis was harmless and does not require reversal. See Snesrud v. Instant Web, Inc., 484 N.W.2d 423, 428 (Minn. App. 1992) (citing Minn. R. Civ. P. 61), review denied (Minn. June 17, 1992).

 III.

The city contends that the district court abused its discretion by admitting the testimony of Hopwood's expert witness, arguing that Bouza was not qualified to testify as an expert witness. Evidentiary rulings, including a decision to exclude expert testimony, lie within the sound discretion of the district court. Benson v. Northern Gopher Enters., Inc., 455 N.W.2d 444, 445-46 (Minn. 1990). Even if this court would have reached a different conclusion as to the sufficiency of the foundation, the decision of the district judge will not be reversed absent clear abuse of discretion. Reinhardt v. Colton, 337 N.W.2d 88, 92 n.1 (Minn. 1983).

Minn. R. Evid. 702 states that an expert may testify

[i]f scientific, technical, or other specialized knowledge will assist the trier of fact to understand the evidence or to determine a fact in issue.

An expert witness must have both sufficient knowledge and "some practical experience" with the subject matter of the proposed testimony. Cornfeldt v. Tongen, 262 N.W.2d 684, 692 (Minn. 1977).

In this case, Bouza testified that he was employed by the New York City Police Department for 23 years and that he was the Police Chief in Minneapolis for eight years. During his time with the NYPD, Bouza helped to shape the police procedure manual for that police department and supervised over 3,000 officers as an Assistant Chief Inspector. Bouza received a master's degree in public administration from the City College of New York.

The record supports the district court's finding that Bouza was qualified to give expert testimony. The critical portions of Bouza's testimony relate to the manner in which the St. Paul Police Department reacted to charges of misconduct by one of its officers. Bouza's expertise in police administration qualifies him to testify on such a subject. The city also argues that Bouza was unqualified because he had no prior professional relationship with the City of St. Paul. Because Bouza's opinion testimony was not based on his knowledge of the city's police procedure manuals, this argument lacks merit. Bouza's opinion was based on his experience in the field and the general responsibilities and duties of police administrators. The district court did not abuse its discretion in allowing Bouza's testimony on this subject.

 IV.

The city contends that the district court erroneously awarded expert witness fees to Hopwood. A discretionary award of expert witness fees will be disturbed only in cases where an abuse of discretion is apparent. Carpenter v. Mattison, 300 Minn. 273, 280, 219 N.W.2d 625, 631 (1974).

Costs and disbursements shall be allowed as provided by statute. Minn. R. Civ. P. 54.04. Rule 54.04 requires those who petition for costs to state the costs in detail and verify the costs by affidavit. Minn. Stat. § 357.25 (1996) permits the district court to allow expert witness fees that are "just and reasonable." As the Minnesota Supreme Court has noted:

This statutory provision sets no maximum limits on the awardable amount, but expressly vests the trial judge with discretion to allow "such fees or compensation as, in his judgment may be just and reasonable."

 Carpenter, 300 Minn. at 280, 219 N.W.2d at 631 (quoting Minn. Stat. § 357.25 (1972)).

In this case, Hopwood requested $5,850.00 in expert witness fees. The district court noted that this request was not supported by documentation, determined that the request was unreasonable and awarded Hopwood $1,600.00 ($400 per hour for four hours). This determination did not represent an abuse of discretion.

The city also argues that, in an action taken under Chapter 363, only the state may be awarded expert witness fees. Minn. Stat. § 363.14, subd. 3 (1996) states:

In any action or proceeding brought pursuant to this section the court, in its discretion, may allow the prevailing party a reasonable attorney's fee as part of the costs. In any case brought by the department, the court shall order a respondent who * * * engaged in an unfair discriminatory practice to reimburse the department and the attorney general for all * * * court costs.

As the city correctly notes, only the department of human rights is entitled to fees and costs under the section 363.14, subd. 3. However, the statute also grants a district court the discretion to award expert witness fees in cases where the plaintiff is not the department of human rights. Accordingly, the district court's award of expert witness fees was not contrary to section 363.14, subd. 3.

 V.

Hopwood argues that the district court abused its discretion in awarding attorney fees. A district court's decision on the reasonableness of costs is subject to review under an abuse of discretion standard. Koop v. Independent Sch. Dist. No. 624, 505 N.W.2d 93, 94 (Minn. App. 1993).

Both Title VII and the MHRA specifically provide for the recovery of reasonable attorney fees by prevailing parties. See 42 U.S.C. § 2000e-5(k) (1994); Minn. Stat. § 363.14, subd. 3. The legislative goal is to provide a reasonable fee, one that is adequate to attract competent counsel without producing a windfall to attorneys. Shepard v. City of St. Paul, 380 N.W.2d 140, 143 (Minn. App. 1985) (citing Blum v. Stenson, 465 U.S. 886, 897, 104 S. Ct. 1541, 1548 (1984)).

The seminal case addressing the analysis to be employed in awarding attorneys fees is Hensley v. Eckerhart, 461 U.S. 424, 103 S. Ct. 1933 (1983). Under Hensley, the method by which a reasonable fee is calculated is to multiply the reasonable hourly rate by the hours reasonably expended. 461 U.S. at 433, 103 S. Ct. at 1939. When the reasonableness of attorneys fees is challenged, the district court must not only make a decision on the claim but also must provide a "concise but clear explanation of its reasons for the fee award." Anderson v. Hunter, Keith, Marshall & Co., Inc., 417 N.W.2d 619, 629 (1988) (quoting Hensley, 461 U.S. at 437, 103 S. Ct. at 1941)).

As in Hensley, the district court considered the complexity of the legal issues involved and the successful manner in which Hopwood's attorneys proved a pattern of harassing conduct and reprisal. The district court noted that Hopwood prevailed on only one of her four original claims. Additionally, the district court reduced the number of hours billed by Ms. O'Connor during the time that both she and Mr. O'Connor were jointly involved in the proceedings. Because the district court followed the procedures outlined in Hensley, the award of attorney fees did not represent an abuse of discretion.

 VI.

Lastly, Hopwood argues that the post-trial judge should have disqualified himself, arguing that the court's failure to do so violated Canon 3(D)(1)(b) of the Code of Judicial Conduct. That canon states that a judge should disqualify himself when "a lawyer with whom the judge previously practiced law" worked on the case at issue during the judge's and the lawyer's previous association. Minn. Code Jud. Conduct 3(D)(1)(b).

Apparently, the post-trial judge did work in the Office of the St. Paul City Attorney during the earlier stages of the litigation. However, Minn. R. Civ. P. 63.03 explicitly makes and "affirmative showing of prejudice" the sole ground for removing a successor judge. Nachtsheim v. Wartnick, 411 N.W.2d 882, 891 (Minn. App. 1987), review denied (Minn. Oct. 28, 1987). The post-trial judge was not the trier of fact and only considered the post-trial motions regarding attorney fees, costs, and expert witness costs. All his rulings are on the record, and they show that the motions were considered fairly. For these reasons, Hopwood failed to demonstrate any prejudice, and the post-trial judge's failure to remove himself is does not require reversal.

Moreover, Hopwood did not comply with the requirement of Minn. R. Civ. P. 63.03 that a party serve a notice to remove within ten days after the party receives notice of which judge will preside. In this case, Hopwood's letter requesting disqualification was delivered one month after the assignment of the post-trial judge. For each of the foregoing reasons, the post-trial judge's failure to remove himself was not reversible error.

Affirmed.

[*] Retired judge of the district court, serving as judge of the Minnesota Court of Appeals pursuant to Minn. Const. art. VI, § 10.