Walt Bennett Ford, Inc. (Appellant) appeals the district court’s1 decision dismissing Appellant’s claims against Billy Goyne (Goyne) for alleged violation of both federal 2 and state3 “odométer rollback” laws. Specifically, Appellant, argues that the district court incorrectly interpreted the knowledge and intent requirements of both the Arkansas and federal odometer rollback statutes; that the district court improperly employed the affirmative defense of equitable estoppel when that defense was never raised by Goyne at trial; and, if the equitable estoppel defense was properly before the district court, Goyne did not put on evidence sufficient to prove each element.
On May 16, 1991, Goyne purchased a new 1990 Ford Ranger truck from Appellant and received a trade-in allowance of $4,000 on his 1986 Chevrolet Celebrity. The Celebrity’s odometer displayed 28,454 miles, when in fact the odometer had turned over. After Goyne and Appellant’s employee, Mr. Haas, reached an agreement on the ultimate purchase price of the Ford Ranger, Goyne met with another employee, Mr. Pruitt, for purposes of completing the odometer disclosure statement. Mr. Pruitt typed in the existing miles — 28,454—and gave the form to Goyne for his signature. At this time, Goyne disclosed to Mr. Pruitt that the stated mileage was incorrect; however, Goyne signed the disclosure statement based on assurances by Mr. Pruitt, a former state police officer, that the only mileage to be reported was the actual mileage shown on the odometer. When Appellant finally received the title to the Celebrity,4 the actual mileage was shown to be 70,358 miles.
Regarding the first issue, we find no error in the district court’s interpretation of either federal or Arkansas odometer rollback law. Federal law mandates a finding of “intent to defraud,” 15 U.S.C. § 1989 (1982 & Supp.1990); Arkansas law, however, requires only proof of an intentional violation of a known duty: “the state need not show any intent to defraud or any evil purpose.” Boren v. State, 297 Ark. 220, 233, 761 S.W.2d 885 (1988).
The district court determined that Goyne lacked the “intent to defraud” necessary to run afoul of federal law.5 We see no clear error in this finding. At the same time, the district court conceded that Goyne’s knowledge that his odometer was inaccurate, plus his subsequent signing of the disclosure statement, was in violation of Arkansas law. During his negotiations *605with Appellant, however, Goyne was assured by Appellant’s employee, Mr. Pruitt, that the incorrect odometer reading was not a problem. Because Goyne relied on Pruitt’s representations when he signed the disclosure statement, the district court invoked the doctrine of equitable estoppel.
The district court correctly points out in its Memorandum Opinion (June 18, 1991; See Appendix, p. 22), that the issue of equitable estoppel, though not specifically and affirmatively pleaded in accordance with Fed.R.Civ.P. 8(c), was raised in Goyne’s response to Appellant’s motion for summary judgment and proof which established the defense was presented at trial without objection. According to Fed. R.Civ.P. 15(b), “[w]hen issues not raised by the pleadings are tried by express or implied consent of the parties, they shall be treated in all respects as of they had been raised in the pleadings.” Accordingly, under Arkansas law, there are four necessary elements of estoppel:
(1) the party to be estopped must know the facts; (2) he must intend that his conduct shall be acted on or must so act that the party asserting the estoppel had a right to believe it is so intended; (3) the latter must be ignorant of the true facts; and (4) he must rely on the former’s conduct to his injury.
The district court properly determined that (1) Mr. Pruitt was Appellant’s employee and Pruitt’s knowledge and information about the odometer disclosure requirements were imputed to Appellant; (2) Pruitt assured Goyne that the odometer disclosure statement showing 28,454 miles was correct under the law and Goyne had every right to believe him since Mr. Pruitt was Appellant’s employee and a former state policeman; (3) Goyne was ignorant of the true facts, in that Goyne was not aware, and had no reason to be aware, that Pruitt’s assurances regarding odometer disclosure requirements were untrue; and (4) Goyne relied on Appellant’s representations to his detriment, in that Goyne’s signature on the disclosure statement, which admittedly reflected inaccurate mileage, violated Arkansas odometer rollback law and subjected Goyne to possible penalties. Joint Appendix, No. 16, Memorandum Opinion, p. 23-24.
We find no error in the district court’s interpretation and application of the doctrine of equitable estoppel. Initially, Goyne disclosed to Appellant his doubts about the accuracy of his odometer; Mr. Pruitt, however, assured Goyne that his concerns were unfounded. In its brief, Appellant places great emphasis on the fact that Goyne’s meeting with Pruitt took place after the trade-in price had been determined. Nevertheless, the fact remains that, at whatever juncture in the negotiation the odometer disclosure took place, Goyne — when first confronted with the odometer’s accuracy — revealed that the odometer reading was incorrect. Goyne was assured that he need not worry about the undisclosed mileage. With that, Appellant is estopped from now raising Goyne’s knowledge of the odometer’s accuracy, and the decision of the district court is AFFIRMED.
. The Honorable Susan Webber Wright, District Judge, United States District Court, Eastern District of Arkansas.
. 15 U.S.C. § 1988 (1982 & Supp.1990).
. Ark.Code Ann. § 4-90-206 (Supp.1989).
. When Goyne negotiated his trade-in with Appellant, he did not have the title to the Celebrity with him. Goyne signed papers, however, which enabled Appellant to obtain a replacement title.
.Section 1989 of Title 15, which addresses civil action for violations of the odometer requirements, states:
(a) Any person who, with intent to defraud, violates any requirement under this title shall be liable in an amount equal to the sum of—
(1) three times the amount of actual damages sustained or $1,500, whichever is greater; and
(2) in the case of any successful , action to enforce the foregoing liability, the costs of the action together with reasonable attorney fees as determined by the court.