Raymond (Rocky) Latham, 68, indicted last month in Prince George's and Montgomery counties on charges of molesting boys, is a three-time sex offender.

A former civil engineer, he was convicted of sex offenses with minors in 1953, according to court records. In the 30 years since, he has been in and out of prison on two similar convictions. He is, say law enforcement officials who know him, the kind of criminal who gives meaning to the phrase revolving-door justice.

Latham had served 16 months of a 16-year sentence at the Maryland Correctional Institute in Jessup when he was paroled on Sept. 17 of last year. Between then and May of this year, when he was arrested, he molested 10 boys in Prince George's and Montgomery counties, police charge.

He is being held in the Montgomery County Detention Center awaiting trial on those charges while his attorney, Thomas Heeney Jr., prepares his defense.

Prince George's Circuit Court Judge Ernest Loveless, who gave Latham the 16-year sentence, said when he heard Latham was out again, "I was shocked and surprised. . . . I virtually thought I had given him a sentence for the rest of his life." Latham has served 11 years in prison, according to court records, nine of those for his first conviction.

Courts in most jurisdictions, including Maryland, Virginia and the District of Columbia, are reluctant to keep child molesters in jail, and prefer to treat them with psychiatric help, and lawyers familiar with Latham's case say there is a reluctance to imprison elderly people.

William Hobson, a Connecticut psychotherapist who works with sex offenders, said prison may only exacerbate the problems of child molesters, many of whom have difficulty relating to adults. Also, molesters are at the very bottom of the prison caste system and may be abused by other inmates.

Neither state nor federal authorities have any good idea how many molesters there are in this country. Studies have shown that one of every four boys will be molested at least once in his life, and one of every three girls, but in the majority of those cases, the molester is a relative of the victim.

Repeat offenders such as Latham are unusual, authorities say. Latham was first arrested for a sex offense in Florida in 1942, according to an FBI statement in Latham's presentencing report. Later in Columbus, Ohio, he was convicted of 14 counts of sodomy against minors and served time in the Ohio prison system from 1953 to 1962, according to the FBI report. He also served eight months in jail in Howard County on sex offenses after a 1974 conviction, according to the FBI report.

He was arrested in December 1977 on charges of sex offenses involving boys in Prince George's County. In September 1979, on the advice of Steny Hoyer, his attorney at the time, he agreed to plead guilty to second- and third-degree sex offenses involving two boys.

Judge Loveless gave Latham a suspended 20-year sentence and put him on five-years' probation on the condition that he participate in the pedophiliac therapy program at Johns Hopkins Hospital in Baltimore.

The program, headed by Dr. Fred Berlin, treats sex offenders with psychiatric counseling and libido-reducing injections of Depo-Provera, a controversial drug used in other countries as a contraceptive for women.

In a letter to The Washington Post last week, Latham said the Depo-Provera was "successful. I took it. . . for 18 months" beginning in 1980. But because of Latham's age, Berlin did not put him back on the drug last year.

But Berlin reported to the courts and the state parole department that Latham was not the best candidate for the therapy program because Latham strongly believes that there is nothing wrong with sex between men and boys.

"We have a program to help people help themselves," Berlin said last week, adding that he has recommended that Latham be let out of jail only if he can be put in a highly supervised setting.

In January 1981, Latham was found to have violated a condition of his 1979 probation that said he should not associate with those younger than 18. According to court records, Latham had taken a 15-year-old boy into his care and enrolled him in a special program for dyslexic children. The boy's mother had tranferred custody of the boy to Latham because she could not handle his truancy. Court records indicate that no sexual contact was reported between Latham and the boy.

While court officials and mental health specialists were researching sentencing alternatives for Latham, he disappeared. A bench warrant for his arrest was issued and when police found him, he was on his way to Europe, passport, ticket and cash in hand. In May 1981, Judge Loveless gave Latham the 16-year sentence for violating the terms of his probation.

Before that sentencing, court records show that Latham's second ex-wife, Maria Latham, wrote the judge asking that Latham be put away for life. And a parole agent wrote, "This agent feels that Mr. Latham's lifelong history of pedophilia constitutes a serious threat to the safety of the younger members of society."

A month after the sentencing, Latham wrote to Loveless asking for reconsideration. In that letter he told the judge that he could arrange for members of the North American Man/Boy Love Association to testify on his behalf and he said that he did not harm the boys he loved. The letter continued, "I want you to know that the greatest civilization ever known (Greek society). . . was based on man/boy love as the majority norm."

Latham also wrote to the Maryland parole commission, which paroled him despite a letter from and conversations with representatives of the Prince George's State's Attorney's Office pointing out Latham's history of offenses involving children. Beverly Marable, spokeswoman for the parole commission, said the commissioners would not explain their decision. She added, "The commission took the letter from the state's attorney into consideration, but it did not change their minds."

Mental health experts who work with molesters say most have experienced sexual abuse during their childhood. Latham's oldest brother said recently that they had a normal childhood.

Latham and his two older brothers moved from Columbus to Florida in the 1930s, according to the oldest brother, who asked not to be identified. The brother said that he had not heard from Latham in five years, that Latham had embarrassed the family and that Latham is "the type of person who should be put away."

Latham is a bright man, most authorities agree. An engineer for a construction firm that worked on several Metro stations between 1972 and 1975, he also worked on the subway system in San Francisco and supervised construction projects for the U.S. Department of Defense in Korea and Vietnam, according to attorney Heeney. When arrested recently in Montgomery County, Latham was operating a small painting contracting firm.

He gives the impression "that in every other way, he is a positive citizen," says his former attorney Hoyer, now a U.S. representative.

Police call Latham a "pied piper" who befriends boys from poor and broken homes and treats them to pizza and ice skating, new clothes and trips to amusement parks.

In January of this year, Latham took two boys with him to Johns Hopkins Hospital, according to Prince George's police. He left them in the car while he went to his therapy session and, in his absence, the boys smashed the car into the side of a building.

In February, a resident at the apartment complex on Old Stage Coach Road in Laurel, where Latham was living, told Prince George's police Latham seemed to have a steady flow of children through his apartment, which he shared with his 14-year-old daughter.

That report prompted a police investigation and surveillance that spilled into Montgomery County when Latham moved to Silver Spring. Police arrested Latham in Montgomery County on May 24.

Latham now faces a 22-count indictment in Montgomery County and 19 counts in Prince George's on the sex offenses. In addition, he has been charged with fraudulently obtaining a gasoline credit card in the name of John Lewis Turner, one of four aliases police say he uses.

Defense lawyer Heeney said that what his client "really wants is an opportunity to get some help and overcome the pedophilia problem." Heeney said that he will try to get Latham into Patuxent Institution, a state corrections mental facility. In addition to the time Latham will have to serve if he is found guilty on the new sex charges, he could face up to 14 years in prison for violating parole, Heeney said.

Latham said he spends his time in jail writing an adventure story about a boy and a sailing trip up the Chesapeake Bay. "It involves a boy overboard, much love, very little sex, an arrest, a suicide and a flight to Nassau," he said.