Two men at the center of the Mischelle Lawless homicide investigation since the beginning of the case in 1992 will take polygraph tests Tuesday in an attempt to clear their names.

“I’m tired of all the bulls---,” Matt Abbott said.

Twin brothers Matt and Mark Abbott will undergo a two-hour polygraph session with certified polygraph practitioner Lee Boyd of St. Louis under the supervision of private investigator John Mackey beginning at 9 a.m. Tuesday in Cape Girardeau.

Matt and Mark Abbott are paying for the test.

“There’s a lot of defamation of character flying around,” Mackey said. “Matt and Mark are constantly being harassed.”

Polygraph tests often are inadmissible as evidence in court. The validity of tests is questionable because “no evidence that any pattern of physiological reactions is unique to deception,” according to an American Psychological Association study from 2004.

The study found an honest person may seem to show deception if he or she is nervous; also, a person who believes a lie strongly could throw off the test.

Countermeasures also can be used to beat the test, including “physical movements, psychological interventions (e.g., manipulating subjects’ beliefs about the test), and the use of pharmacological agents that alter arousal patterns,” according to the study.

“Me personally, I don’t believe in either of them,” former Scott County sheriff Rick Walter said of polygraph and computer voice stress-analyzer tests.

Lawless was found dead in her car Nov. 8, 1992, at the northbound Highway 77 exit ramp off Interstate 55 in Benton, Missouri. She had been shot three times and struck in the head with a heavy object.

Josh Kezer, a teenager from Kankakee, Illinois, spent 16 years in prison after jailhouse informants claimed he had killed the 19-year-old nursing student.

Walter re-opened the case in 2008, which ultimately led to the exoneration of Kezer a year later.

“They can beat it. ... No, it’s not admissible, and there’s a reason why,” Walter said.

Mark Abbott took a computer voice stress-analyzer test with a tester from the Missouri Attorney General’s Office shortly after Walter reopened the Lawless investigation in 2008. The test indicated signs of deception in Mark Abbott’s answers, Walter said.

“It means nothing,” Walter said of the test result.

Kezer, who was convicted for Lawless’ murder but later was declared innocent and released from prison, wrote in an email he believes polygraph tests are unreliable and can be manipulated by the test-taker and administrator.

He said the only way the Lawless murder would be solved is with honest investigation.

“Angela Mischelle Lawless and her family deserve justice,” Kezer wrote. “Sheriff Bill Ferrell pursued injustice. Sheriff Rick Walter pursued justice. Sheriff Wes Drury and the investigators he’s appointed to the Lawless investigation haven’t historically instilled confidence in their ability to investigate the Angela Mischelle Lawless murder appropriately, given their loyalty to ex-sheriff William F. Ferrell. I believe their loyalties to Ferrell will cloud their judgment. Maybe I’m wrong. Maybe I’m right. Time will tell.”

Testimony from Mark Abbott incorrectly placed Kezer near the scene of the crime in a white vehicle that was driven away shortly after Mark Abbott found Lawless dead.

Police reported a man claiming to be Matt Abbott reported the shooting at the sheriff’s office the night of the murder.

Matt Abbott said his brother never claimed to be him when he arrived at the sheriff’s office to report finding Lawless dead.

He said Wes Drury, who was working up front in the sheriff’s office that night, assumed it was Matt Abbott, and Mark never corrected him.

Drury recently unseated Walter as the sheriff of Scott County. Two messages left on Drury’s cellphone and three messages left with administrative assistants at the sheriff’s office Friday were not returned by Friday night.

Matt Abbott said his brother was pressured by Ferrell into testifying. When Mark Abbott was presented with a lineup, an investigator with the Missouri State Highway Patrol already had told Abbott the suspect in the Lawless murder was in the lineup, according to documents. Kezer’s photo was the only one emblazoned with the words “police department.”

During a telephone interview Friday, Matt Abbott made several statements that contradicted law enforcement’s statements about the case and said Walter has lied about certain interactions.

Matt Abbott said investigators did not meet him at his home to ask about him coming into the office shortly after the murder. Walter said there are records of that interaction taking place.

Matt Abbott also claimed in an interview Friday he paid Walter to test his DNA against DNA found at the scene. Walter said he did not accept a payment from Matt Abbott and did not ask for a payment.

Matt Abbott said Walter never tried to contact him again after Matt Abbott threatened the sheriff and another investigator in 2012 or 2013. Walter said that threatening message never happened, and he has tried to interview Matt Abbott several times over the last several years.

Matt Abbott said Friday he did not know Lawless before he was shown her photo by investigators. He said investigators checked his phone records and all phone records of his family members, and there were never any calls made to Lawless.

“What did I do, did I write her a letter?” Matt Abbott said. “What did I do, send her a kite?”

Later, he said Lawless had a reputation for being promiscuous and said one of her partners could have been her killer.

“It would seem odd, since he wouldn’t know who she is and would make a comment like that,” Walter said.

Lawless’ friends told investigators and reporters she knew the Abbotts.

The only civilian connected to the Lawless crime scene by evidence publicly known is Mark Abbott. He admitted he discovered Lawless’ body and touched her on the shoulder the night of the murder.

Matt Abbott said Friday his brother was stopped at the stop sign before turning onto Highway 77. He looked in his rearview mirror and thought Lawless was drunk, which is why he got out of his vehicle and went to her vehicle, Matt Abbott said.

Matt Abbott said it would be unusual for his brother to stop for someone on the side of the road.

Mark Abbott talked about seeing people in a white vehicle shortly before going to a payphone. The description of those people has changed throughout the investigation — from Mexicans to a black man from Sikeston to Josh Kezer, according to Walter.

Matt Abbott said Friday his brother actually saw an interracial man.

Matt Abbott said Friday on the night of the murder he was in Sikeston and went with a friend to Benton.

“I’ve never held a gun in my life,” Matt Abbott said. “I’ve never shot a pistol.”

bkleine@semissourian.com

(573) 388-3644

Pertinent address: 2711 Thomas Dr., Suite 106, Cape Girardeau, MO