DENVER -- Weld County District Attorney Ken Buck cleared a Fort Collins detective and prosecutors of wrongdoing in putting together a murder case against a man whose conviction was overturned because of new DNA evidence.

In a statement released Tuesday, Buck said he found no criminal conduct but did find disturbing flaws in the investigation and prosecution of Timothy Masters.

Masters' was the first person in Colorado released from prison because of DNA evidence.

Masters' defense attorneys said lead detective Jim Broderick may have perjured himself and illegally eavesdropped on him, and that overzealous prosecutors ignored evidence that could have cleared Masters of the 1987 slaying of Peggy Hettrick. Buck was appointed special prosecutor to investigate the case from neighboring Larimer County.

In a letter, Buck said deficiencies in the case were a result of "misfeasance not malfeasance."

Messages left for Masters, who was freed from prison in January after 9 1/2 years, and for Maria Liu, one of Masters' attorneys, were not immediately returned.

"Weld County gave Jim Broderick the presumption of innocence Larimer County didn't give me," Masters said in a statement given by Masters to Denver station KUSA-TV.

"But this time there's no closure for the Hettrick family. And there's no closure for us. Period. Unless they can solve her murder, y'know, and get the right person in prison," said John Masters, Tim's uncle.

Buck was responsible for determining whether Broderick broke any laws, but in a letter to Chief Judge James H. Hiatt, he said it was important to give context of the overall case, which he used to reach his conclusions.

"After consideration of the evidence, I did not discover criminal conduct among employees of the Fort Collins Police Department or the prosecutors in the case," Buck wrote.

Broderick is out of state dealing with a family medical issue and not available for comment, said Fort Collins police spokeswoman Rita Davis. She said the department will open its own internal investigation, which are usually completed in about 45 days.

Davis said Police Chief Dennis Harrison was not surprised that Buck found no criminal wrongdoing, but that the department had not yet reviewed Buck's report.

Buck interviewed at least 28 people, including police officers who investigated the case.

The allegation of eavesdropping centered on whether Broderick secretly taped a conversation between Masters and his father, Clyde, in February 1987, the day after Hettrick's body was found in a field about 100 feet from Masters' bedroom. Clyde Masters died in 1996, two years before Masters' arrest.

Buck concluded that Broderick was asked by a supervisor to tape the conversation and was not responsible for obtaining consent. In addition, Buck noted that the statute of limitations had run out.

However, Buck questioned why Masters' defense attorneys in 1999 had a transcript of the police interview that did not include the conversation between Masters and his father. The transcript given to defense attorneys only noted that a conversation happened.

Buck's report said in part: "Masters withstood a blistering barrage of questions from his father and convincingly maintained his innocence throughout. This evidence may have been relevant at trial to demonstrate Tim Masters' state of mind a day after the murder of Peggy Hettrick."

Buck said the omission of the conversation was not a criminal act because prosecutors had given defense attorneys the tape of Masters' interview, which included the conversation, and Broderick also documented the conversation in a police report. Buck concluded that Broderick's explanation, that the conversation was omitted from defense transcripts because of questions about whether that conversation would be admissible evidence, seemed plausible.

Broderick also faced perjury allegations for saying he wasn't involved in the Hettrick investigation in the years immediately following the slaying and for saying there was only one footprint in field that defense attorneys believe belonged to the actual killer.

Buck concluded that Broderick did not participate in Hettrick's investigation in a meaningful way. He also said Broderick's testimony in 1999 about finding only one Thom McAn footprint at the scene was the result of "poor crime scene analysis," and was "not criminal in nature," Buck wrote.

If testimony had included information about other Thom McAn footprints: "The jury would have had evidence to conclude that another individual wearing Thom McAn shoes -- not Tim Masters -- was in fact the perpetrator or an accomplice to the murder if Lt. Broderick had testified completely," Buck wrote.

The Colorado Supreme Court's Office of Attorney Regulation in January announced it would investigate whether the two former prosecutors acted improperly. Terry Gilmore and Jolene Blair are now state judges.