SAN DIEGO -- "He raped my daughter, he's a sex offender," a local mother named Maryanne said.

A four-year-old girl, a preschooler, was raped by her 14-year-old cousin.

"She was so tiny and so young, and he's such a monster," Maryanne added.

For six years, the rape remained a secret until the little girl turned 10 and finally told her mother.

The cousin, 20 years old when the rape was finally revealed, admitted to the crime. He was treated as a juvenile because he was 14 at the time of the rape.

Because of the juvenile ruling, his records remain sealed and his name can't be made public.

He spent 9 weeks in jail and was placed on probation, records indicated.

It is a punishment Maryanne considered too lenient.

"The laws have to be changed," said Maryanne.

There is much debate over what to do about the 40 percent increase in sexually based cases involving juveniles over the last two decades.

The Associated Press reported in 1985 that 24,100 juveniles were accused of rape, violent and non-violent sex offenses. That jumped to 33,800 in 2004.

The increase is explained at least in part by more reporting and tougher rules. It is unclear whether society is raising more young sex offenders.

Pamela Sternaman, a supervising probation officer with the San Diego Juvenile Sex Offender Management Program, said, "We have approximately 158 that are active in our unit right now."

Sternaman said the youth in the program, ranging from age 9 to 18, often share characteristics that explain their sexually inappropriate or aggressive behavior, such as poor social skills, low IQ and low self-esteem.

"Some of our youth are acting out, sexually curious and haven't learned what's appropriate or what's not," said Sternaman.

In the juvenile system, the focus is on rehabilitation. Unlike adult offenders, juveniles respond well to treatment and counseling, according to experts.

Child psychologist Dr. Lisa Boesky said, "Juvenile sex offenders, the majority of them, never offend again. I think the rates are maybe 5 to 14 percent that they ever offend again."

Some parents of victims said they don’t care about the statistics. They said they want harsher penalties for offenders.

Another local mother said, "This is a sickness; it's a disease."

The woman's 8-year-old boy was molested by Nicolas Shur when Shur was 18 and working as a counselor at a YMCA skate camp. When the boy came forward, 2 other victims were found.

"His spirit was crushed by an adult he trusted," said the boy's mother.

While the courts never proved it, the victims were convinced Shur started molesting children before he had turned 18.

Studies showed one in 2 adult sex offenders began their sexually abusive behavior as juveniles.

"In some states they actually castrate pedophiles, because there is no other way to stop them, and I'm a little sorry we don't live in that state," added the mother.

Shur is serving 10 years in state prison and will have to register as a sex offender for life.

The 14-year-old who raped his 4-year-old cousin, treated as a juvenile, was not listed on any public sex offender registries.

States like Delaware, South Carolina, and Texas can post photos, names and addresses of juvenile offenders.

California is one state that does not take those steps.

Boesky said, "If we call them a sex offender, if we have them register as a sex offender, think of what that does to their self esteem… "

Boesky said she believed decisions should be made case by case, but in general, she said forcing kids to register will prevent them from turning their lives around.

To some victim's parents, that is something of little concern.

"He should have been put away for life," the mother said.

There is a push to get tougher on juvenile sex offenders.

At the federal level, the Adam Walsh Act calls on states to name and publicize young and teen offenders.

California is grappling with how to implement the law fairly, according to experts.

Some experts believe access to sex and pornography in the media and online is contributing to more juvenile sex offender cases.

Others think that school districts, social services and parents are now reporting behavior that in the past would be considered a normal part of growing up.