Oct. 16, 2003 -- Bruce McLaughlin was once known as a successful attorney, loving husband and dedicated father of four adoring children.
Now, his reaction to a strange test — a kind of penile sensor that's meant to be a kind of a sexual lie detector — may mean the difference between freedom and jail.
McLaughlin's problems began when he and wife, Robyn, broke up after 16 years of marriage. And things only got worse — Bruce McLaughlin ended up in prison on charges of sexually abusing three of his four children.
By the time ABCNEWS' Primetime met Bruce last November, he had already spent 4 ½ years behind bars for a crime he insists he didn't commit.
"I wouldn't wish this on anybody who has had to go through what I've gone through," he said.
One night, almost seven years ago, Bruce and Robyn McLaughlin had a fight at home.
Robyn said there had been domestic violence before but this particular night was "the last straw."
She complained of a twisted arm and was taken to the hospital. Bruce was arrested, charged with assault and barred from the family home. The charges were later dropped and Bruce claimed any physical abuse was mutual.
But Robyn filed for divorce and custody of the children immediately became an issue. Saying he wanted to be a better, more honest husband, Bruce wrote a letter to Robyn revealing he had cheated on her.
The confession of infidelity ended any chance of reconciliation. Then, almost two years after the couple separated, Bruce was arrested and charged with 26 counts of child sexual abuse.
From the very start, Bruce maintained he was wrongly accused. But there was dramatic, convincing testimony against him from his own children.
Bruce McLaughlin was convicted of child sexual abuse against three of his four children and sentenced to 13 years in prison.
New Lawyer, New Evidence
In prison, Bruce hired a new lawyer, Alex Levay, to help him win a new trial. Reviewing the case, Levay noticed inconsistencies — evidence never presented at Bruce's first trial.
For example, Levay discovered handwritten notes the McLaughlin children had in their possession during police questioning. The notes were prepared with the help of their mother, he said.
Robyn denied she concocted her children's stories of sexual abuse by her estranged husband, but said the girls were so young at the time that she had to write the notes for them.
There was also another strange twist in the story. Throughout the ordeal, Robyn McLaughlin was getting advice from Martin Sayer, an evangelical pastor.
Primetime obtained a series of faxes between the two. In one, Sayer offered Robyn suggestions on how to persuade her children to talk about their father's alleged abuse. In another, Sayer proposed that Robyn show her husband's "infidelity letter" to the couple's oldest son.
One fax from Robyn said: "Of course Satan's voice is trying to tell me that I have put the children up to this. But thank God that the Holy Spirit has a louder voice."
Asked if she made her children's allegations up, Robyn said, "I would never do that."
Levay also questioned Stanton Samenow, the court-appointed psychologist who had evaluated the McLaughlin children.
Samenow said while he believes Bruce has control issues, he says this case simply does not fit the pattern of abuse cases involving family members.
"I have never encountered a case in which a parent has abused both male and female offspring, much less all the kids in his family," he said. "I just haven't encountered it. So it would be, to say the least, highly unusual."
Levay convinced a judge to order a new trial with a new jury, and last December, Bruce McLaughlin was acquitted of the charges for which he had already after served more than four years.
After his acquittal, he was granted limited visitation with his children on weekends, and only with adult supervision.
But in March of this year, his wife sought a child protection order after Bruce took the kids snowboarding in the mountains.
Robyn accused Bruce of fondling one of the girls while she sat on her father's lap during the drive home. Bruce denied the allegation "absolutely," saying the car was packed with his three other children, their grandmother and two family friends.
Desperate to prove his innocence, Bruce volunteered to undergo a battery of controversial psychosexual tests. He said he hoped the tests would clear his name once and for all — and he said he wanted the tests publicly witnessed. He agreed to undergo the tests in front of Primetime's cameras.
Meet the PPG
Forensic legal consultant and father's advocate Dean Tong, who set up the tests, said they "have about a 95 to 98 percent degree of specificity and sensitivity, so they're, they're about as reliable as a science as we have out there."
Joseph Plaud, a clinical psychologist who has interviewed hundreds of alleged sexual offenders in and out of prison, conducted the tests on Bruce, which were designed to measure his sexual interests.
First, Bruce was asked to answer hundreds of personal questions about his sexual history and personal life. The interview lasted seven hours.
Then came the most private — and most controversial — part. A gauge called the penile plethysmograph, or PPG, was attached to his penis. The devices measures the change its circumference in the penis when a man hears and sees sexually explicit material.
The PPG has been used in the courts before, as evidence of guilt and to determine a course of treatment for convicts. But some experts say it isn't full-proof.
Ted McIlvenna, president of the Institute for Advanced Study of Human Sexuality in San Francisco, which has one of the machines, said he has stopped using it entirely because the results it gave were inconsistent.
Dr. Fred Berlin, a psychiatrist with the Johns Hopkins University School of Medicine, said positive results could be pretty good evidence, but negative results could mean nothing.
"It's far less powerful evidence than other things such as victim testimony, DNA evidence. It's just one bit of information to take into consideration," he said. "I wouldn't weigh it very heavily."
For 90 minutes, Bruce wore virtual reality goggles that showed him different kinds of suggestive images and allowed him to hear audio of sexually explicit activity.
He was shown an image of a young girl. "So far so good," Plaud said. Bruce was still at or near the base line and it showed no arousal.
He was shown an image of a young boy titled "Coercing a Young Boy to Submit."
"He looks like he's disgusted by what he's hearing," Plaud said. "He's below base line."
Bruce was next shown an image depicting the rape of a young girl. "Sick!" Bruce said, flinching and appearing to become emotionally distressed.
Plaud noted the child would be in the 8- to 10-year-old range — roughly the same age as Bruce's own twin daughters.
Asked if it Bruce could be willing himself to remain unaroused, Plaud said he was also looking at his relative patterns of arousal.
"For human males, we are hard-wired to react sexually. We're not even aware, a lot of times, of just the limits to which we're reacting sexually," he said.
During the entire time Bruce McLaughlin was observed by Primetime, the only time he was ever aroused was during male-female encounters between adults.
Ten hours after the test have begun, Plaud told Bruce: "I do have the data, and they are uniformly positive and very strong, supporting the fact that you have exclusive sexual arousal to adult females in consenting sexual activity. That's just the best way to say it."
The Cycle Starts Again
This past month, Maryland's Child Protective Services ruled out the allegations Bruce's daughter made in March.
Bruce says he is glad he took the test. He considers them a pre-emptive strike, and plans to use them in his defense if new allegations arise.
He also plans to use them during divorce proceeding and hearings involving custody of the children.
Last week, Robyn McLaughlin told Primetime one of her daughters told her therapist her father inappropriately touched her during a game of touch football with her two brothers.
Bruce McLaughlin says, once again, he's been falsely accused.
ABCNEWS' Andrew Chang contributed to this report.