An investigation into former Big Lake Police Chief Matt Hayen found he illegally purchased a firearm for his predecessor by falsifying a firearms transaction record in July.

While no criminal charges have been filed, an independent investigation found Hayen's actions violated the city's code of conduct and were unlawful because he misrepresented the actual buyer of a firearm.

Hayen, 37, resigned last week while the investigation was ongoing, according to City Administrator Clay Wilfahrt. Big Lake's City Council approved his resignation Wednesday.

The city placed Hayen on leave in mid-September following the investigation into a complaint made by former Police Chief Joel Scharf in late August.

Scharf said Hayen altered a letter signed by Wilfahrt allowing Hayen to purchase a firearm for official duties without the standard background check. Scharf also said Hayen signed a firearm transaction record stating Hayen was the buyer of a firearm when it was, in fact, purchased and transferred to a third party.

According to the investigative report, conducted by Isaac Kaufman of Red Cedar Consulting Scharf turned in his city-issued gun when he resigned and told Hayen he was interested in purchasing the gun when the city decided to liquidate it. Scharf, who now lives in Arizona, returned to Minnesota in July and met Hayen on July 28 at a police equipment store in Plymouth.

Scharf intended to buy back his gun using his Minnesota permit to purchase but the seller declined the sale because Scharf did not have a Minnesota address. Hayen, who also planned to purchase a city-liquidated gun, changed the quantity of guns on Wilfahrt's signed letter from "one" to "two."

"There is some ambiguity as to what happened," said Kaufman, whose report acknowledges Hayen may have altered the letter due to carelessness or a lack of familiarity with the process rather than with any intent to deceive or defraud. Hayen told Kaufman both Scharf and the store's staff said the process was fine.

After purchasing the two guns, Hayen signed a firearm transaction record and drafted a bill of sale for Scharf.

Scharf's complaint was referred to Plymouth police to investigate possible criminal violations, as well as the Bureau of Alcohol, Tobacco, Firearms and Explosives and the Federal Bureau of Investigation. Both federal entities submitted findings to the Department of Justice, which declined to prosecute, in part, because the straw purchase involved fewer than 50 guns, according to Kaufman's report.

However, the AFT issued Hayen a warning notice of straw purchasing on Dec. 9 that stated it is unlawful to provide false information on firearms transaction records.

Hayen joined the department in 2016 and was appointed chief in July following the May resignation of Scharf, who had served as Big Lake police chief since 2012 and had spent more than 30 years as an officer. In his resignation letter, Scharf cited a recent diagnosis of post-traumatic stress disorder.

Scharf was also the subject of a criminal investigation by the Minnesota Bureau of Criminal Apprehension involving alleged unfair election practices. The BCA investigation ended without criminal charges filed but Scharf and Hayen "engaged in a heated exchange of e-mails, based in part on what Scharf believed to have been Hayen's role in the BCA investigation" and "the record shows that the relationship between Hayen and Scharf rapidly deteriorated" before Scharf sent the formal complaint to the city administrator, Kaufman's report states.

"This investigator finds that Scharf — who himself was directly implicated in the July 28 transaction at Streicher's — likely had ulterior motives for making his complaint," Kaufman stated.

Scharf could not be reached for comment Thursday.

Hayen said he feels Scharf retaliated against him following the BCA investigation and said he "never would have participated had I better understood the legal technicalities, as I relied on the advice of the federal firearms dealer/retailer and Mr. Scharf."

"When I would not follow Mr. Scharf's directives after his retirement, and after he learned I spoke with the Minnesota Bureau of Criminal Apprehension investigators regarding allegations he improperly campaigned against a city council member, Mr. Scharf retaliated by devising a series of events to remove me as chief," Hayen said in a statement issued by Minneapolis-based attorney Kelly Keegan.

"Believing I was finalizing his employment with the department, I helped him purchase his department-issued firearm — a transaction in which he was the sole beneficiary and an active participant," Hayen continued. "While I wish the outcome could be different and that the city would have been more transparent with this process, to the citizens of Big Lake, the Big Lake city staff and most importantly, to the officers of the Big Lake Police Department, I take responsibility for my actions, and I never had any intention of being dishonest or jeopardizing the public's trust," Hayen said. "I truly enjoyed working for the city of Big Lake and looked forward to a long career serving as your chief."