DOWNEY ( — Twenty-one felons with histories of sexual offense were arrested throughout a three-week period in which an operation — being called the biggest of it’s kind in Los Angeles this year — took place.

“Operation Tracker” consisted of 137 compliance checks and searches that involved felons with a history of sexual offense.

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The operation also resulted in the seizure of a number of computers, hard-drives, and phones. Heroin, methamphetamine, and marijuana were also confiscated.

In addition, children were found at a residence shared by a person who had previously been convicted of sexual offense against children, according to Los Angeles County Department of Probation officer Carol Lin.

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“When you go to a residence, and you find children in the home, it elevates the situation,” said the operation’s lead supervisor Steven Howell. “It is no longer a ‘compliance check’. It is now an investigation. Your investigation focuses on the children.”

According to Probation Department Assistant Chief Margarita Perez, “More than 61 percent (of the probationers) are assessed as high or very high risk. Only one to two percent are low-risk offenders. This is contrary to what we often hear in the media, indicating these offenders are low risk. This is just not the case.”

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