Former Attorney General Paul Morrison won’t face criminal charges for his actions during an extramarital affair that forced him out of office.

Two special prosecutors, Robert Arnold III and Timothy Keck, announced results Wednesday of a nine-month investigation, concluding that Morrison’s conduct did not warrant prosecution. They issued a letter to Johnson County commissioners and District Attorney Phill Kline, who had appointed them to investigate his political opponent.

Kline, who leaves office Jan. 12, said he has “full faith” in the prosecutors’ investigation. Steve Howe, who defeated Kline in the GOP primary in August and will take over as district attorney in January, didn’t return messages left at his office and on his cell phone.

Morrison’s former mistress, Linda Carter, had worked in the Johnson County district attorney’s office for Morrison and Kline. She has alleged that after Morrison became attorney general, he tried to use her to influence a federal lawsuit against Kline and to gather sensitive information on Kline’s investigation of an abortion clinic.

Kline also appointed Arnold and Keck to investigate whether Morrison engaged in blackmail or telephone harassment during his affair or as it soured.

The two prosecutors said they investigated numerous allegations of misconduct, but they specifically mentioned only the telephone harassment allegations.

“There was insufficient evidence to support one or more of the elements of these alleged crimes as well as valid and sustainable defenses to many of these allegations,” their letter read.

Morrison has denied any professional wrongdoing and has accused Kline of waging a “political vendetta.” Kline’s critics note that Keck worked for Kline in the district attorney’s office for about a year before entering private practice with Arnold.

“We promised when we took this on, we would be fair,” Keck said during a news conference Wednesday. “As far as our investigation goes it’s over.”

Trey Pettlon, an Olathe attorney representing Morrison, agreed that the prosecutors were fair.

“Their investigation was deliberate and thorough and has confirmed what we have maintained from the beginning: Paul is not guilty of any criminal wrongdoing. Any allegations to the contrary were misleading and false,” Pettlon said.

In declaring his faith in the special prosecutors, Kline said in a statement: “I am pleased the investigation is completed.”

Carter’s attorney, Brian Russell, of Lawrence, declined to comment.

Arnold and Keck said they spent between $21,000 and $22,000 on their investigation, out of $25,000 the county commission allocated at Kline’s request. Commission Chairwoman Annabeth Surbaugh said she had hoped the prosecutors would release their findings earlier and acknowledged the commission probably would not have sought their appointment without Kline’s request.

But, she said, “The issue needed to be put to rest.”

Kline, an anti-abortion Republican, was attorney general and Morrison, an abortion-rights supporter, was Johnson County district attorney when Morrison switched from the Republican to Democratic parties and successfully challenged Kline’s re-election in 2006. Republicans then chose Kline to finish Morrison’s term as Johnson County district attorney.

Morrison stepped down as attorney general at the end of January 2008, after acknowledging his affair with Carter.

Carter’s version of the affair emerged in two interviews with members of Kline’s staff. She said it began in September 2005 and continued as Morrison ran for attorney general and after he took over that office in January 2007. Carter left the district attorney’s office late that year.

She contends Morrison unsuccessfully pressured her to write letters for eight people who filed a federal lawsuit because Kline fired them after taking over in Johnson County. The former employees eventually dismissed the suit after Kline agreed to write letters saying they weren’t fired for anything they did.

Carter also alleged that Morrison sought inside information about Kline’s investigation of a Planned Parenthood clinic in the Kansas City suburb of Overland Park.

Kline started investigating the clinic as attorney general and continued to so as district attorney. Morrison, as attorney general, reviewed evidence Kline had gathered and concluded in June 2007 that it showed no wrongdoing by the clinic. But Kline filed 107 criminal charges in October 2007, alleging the clinic falsified documents and performed illegal late-term abortions. The clinic has denied the allegations.

Carter also has alleged that when their relationship soured, Morrison threatened to ruin her efforts to find a new job.

Morrison has said many of Carter’s statements are “patently false.”

Arnold and Keck had little to say about their findings on most of the allegations against Morrison.

The prosecutor said they examined whether several phone calls from Morrison to Carter on Oct. 31, 2007, constituted a crime. They said the calls weren’t harassment but “a continuation of their ongoing pattern of behavior.”

Billing records for a cell phone for Carter, paid for by Johnson County, showed she received more than 500 calls in 2007 from one of two cell phones Morrison used, or a phone at his home in Lenexa.