PINELLAS PARK — They found the fliers on their doors in December, bearing the stiff-jawed mug shot of the stranger in Apartment 211.

He was a sex predator, the fliers warned, freed a year earlier after spending nearly 15 in prison.

Michael Shepard told his new neighbors not to worry: It was a Romeo and Juliet affair that got him locked up; a preacher's daughter, her angry father.

Some parents at the Pinellas Park complex believed Shepard. Some even let him babysit.

Others noticed his shifting stories. They held their children more closely, made extra fliers.

They watched as Shepard rode with children on his scooter, gripping their small bodies on the way to the wooded "hideout." They watched him buy them McDonald's, ice cream, video games.

Shepard, 35, kept hidden what really sent him to prison: the three young boys and little girl he sought out and molested. And neighbors didn't know about the psychologists who debated whether he was so dangerous the state should keep him confined.

Now, less than 18 months since his release, Shepard faces 14 new charges of raping or assaulting at least seven children in one of the worst cases of its kind local police can recall.

Shepard manipulated his victims into sex acts, police say, often in front of other children. One girl was 5 years old.

"I'm absolutely devastated over it," said neighbor Rene Oszman, 30. "My heart is broken."

• • •

Shepard's record starts early.

He was 15, cleaning out trucks with a man and his son, when he grabbed the boy and fondled him, a 1995 Pinellas County sheriff's arrest report says. Later, he did the same to the boy's brother. He told police he was getting counseling for a similar offense in South Carolina.

Three years later, Shepard was living in a mobile home park in Largo. He seemed nice, an 11-year-old girl said in a deposition, until he tried to grope her.

She was sitting on a log, her favorite place to think, when Shepard touched her thigh. He leaned in to kiss her, and she ran.

Her 9-year-old brother had more to say. One day, Shepard picked him up and felt inside his shorts, then touched himself. "If you want a piece of candy, you've got to touch me right there," he told the boy.

A lawyer asked: Why do you kids go to Shepard's house?

"The day I met him I thought he was going to be my friend," the boy said. "I didn't know he was going to do that stuff to us."

Shepard got probation.

Near Christmas 1998, a mother needed time to pick up new bikes for her sons, so she dropped the kids off at a Largo roller rink.

Shepard was there, 19, a loner. He gave the boys soda and quarters, the boys recalled in depositions. "You want to play a game?" Shepard asked the 6-year-old. "Come over here." The boy said no. Shepard pulled him closer and reached inside his pants.

Later, Shepard followed the 9-year-old into the restroom, picked him up and touched him, too.

When the boys saw their mother again, they began to scream.

"Mommy, mommy, you'll never guess what happened!"

• • •

Fifteen years later, after the guilty plea and the time served, the state had a chance to keep Shepard locked away.

Florida's involuntary commitment system was born two decades ago, when police discovered the dismembered remains of a 9-year-old boy in a Miami-Dade avocado grove. He had been kidnapped, raped and shot.

The Jimmy Ryce Act requires the state to identify the most dangerous sex criminals — those with a disorder that makes reoffending likely — and commit them to a treatment center after they finish their criminal sentences.

First, the Department of Children and Families screens them.

Next come psychological evaluations and, if probable cause exists to commit the offender, a trial.

If the state can convince a judge or jury, offenders are sent to the Civil Commitment Center in Arcadia, a 720-bed facility with open-bay dorms and shared living space. Once a year, they have a chance to appeal for release.

Critics of the law decry the costly practice of confining people after they've served their time.

Supporters point to the treatment, the process' selectivity, the potential victims protected.

• • •

Shepard's case came down to two doctors.

An initial team of psychologists looked at his files and recommended confinement. Prosecutors filed a petition, and his case went to trial in late 2013.

Martin Falb, the state's expert, couldn't make it to court. He told County Judge Dorothy Vaccaro by phone that he'd diagnosed Shepard with pedophilia, depressive disorder and adult antisocial behavior. He said Shepard was likely to reoffend.

But he waffled in his testimony, admitting he had been "straddling the fence" on Shepard's diagnosis, a Pinellas-Pasco court spokesman said.

Conversely, Karen C. Parker adamantly testified for the defense that Shepard did not qualify for commitment. Unlike Falb, she had interviewed Shepard in person. She was also a former director of the state's Sexually Violent Predator Program.

Messages left for the psychologists by the Tampa Bay Times were not returned.

The judge ruled: Shepard was free to go.

• • •

The Ryce Act does a good job of catching the most dangerous offenders, Executive Assistant State Attorney Kendall Davidson said.

"I'm not sure that there was anything that could be done under the available testimony with the professionals disagreeing," he said of Shepard's trial.

Jeanine Cohen, Shepard's lawyer for the Ryce hearing, said the case against him was weak.

She thinks the act wrongfully warehouses offenders after they have served their time. She said the program's budget of $31.5 million would be better spent on treatment of offenders while in prison and on educating families about safety.

"You say to yourself, who would let a predator be alone with their children?" she said. Even if he is guilty, she said, "it's terrible, but it doesn't mean the system failed."

Few sex criminals meet the criteria for commitment. Of 55,000 offenders referred to the program since the late 1990s, prosecutors have filed court petitions for 1,577. Of those, 932 have been committed.

Psychologist Carolyn Stimel was among those who examined Shepard's files. Because evaluations deal in human behavior, she said, they're an imprecise science.

"We're asking to predict the future, which is never very easy," she said. "It's never going to be 100 percent. We just can't do that."

• • •

It was winter when Shepard moved into the Cedar Hollow Apartments, "TROUBLE" tattooed on his arm, a pitchfork on his leg.

All his neighbors knew about him came from the fliers revealing his record: "Lewd, Lascivious Child U/16 (Principal)" and "(Principal in Attempt)."

They didn't know about the inmates he was caught having sex with in prison, or the confrontation with his live-in lover, his stepbrother, that winter.

A month after Shepard arrived, a boy slept over at his apartment.

When the boy awoke, Shepard was beside him in bed. Then, police say, Shepard raped him.

Two months later, Shepard drove two boys on his scooter to the "hideout" where McDonald's wrappers lay among the leaves.

He forced the 8-year-old to kiss him, touch him, perform sex acts on him, police say. Then, they say, he raped the boy and did the same to the 10-year-old.

He played a "dare" game there to coerce boys into sex acts for PlayStation games, reports say.

And at a skate park in Largo, he made bets with boys playing basketball, forced them to show him their genitals and sometimes assaulted them, reports say. Once, he made a 12-year-old strip and wrestle him.

While babysitting five children, Shepard undressed and sexually battered a 5-year-old girl at her aunt's house, reports say.

"I've been here 15 years and I cannot remember working (a case) like this," Pinellas Park police spokesman Adam Geissenberger said.

Shepard declined an interview with the Times. Several family members did not return calls for comment.

He denied the crimes at a March hearing. He said children concocted the accusations.

"I've been out of prison for over a year and I've been doing good for that year," Shepard told a judge. "When this all (happened), the three victims are all related to each other and I had a problem with their father over the weekend, and they want me out of the apartment complex I'm living in 'cause I'm a sex offender."

His bail was set at $5 million.

• • •

This month, Shepard's neighbors sat and smoked, wishing they'd heeded the warning signs and lambasting the system for letting him go.

"I'm shocked that he was in for 15 years and gets out with no supervision, and to have this happen is just repulsive," said great-grandmother Vicki Conner, tearing up. "Now five, 10, maybe more children's lives are scarred."

Stephen Greene, 21, said he confronted Shepard to send a clear message: Stay away from my 6-year-old brother. Greene gave extra fliers to residents.

"They were just oblivious," he said of the victims' parents. "They just believed his lies."

Rene Oszman, 30, was among those Shepard initially convinced.

"At first I was trying to give him the benefit of the doubt because we've all been that age and we've all made mistakes," she said. But the red flags quickly began to multiply, she said. She noticed the age of the fabled preacher's daughter often changed.

And she watched with a sense of dread as children took turns with Shepard on his scooter.

"They had these big old smiles," she said. "But over time it was just like their faces went to neutral. There was no fear, no joy, no smiles, nothing."

Times researcher Carolyn Edds contrib-uted to this report. Contact Claire McNeill at cmcneill@tampabay.com.