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'Obviously, it happened': Taped call with teen victim buries Chandler man accused of assault in apartment pool

Published August 21, 2026 5:03 PM MST

Robert Mark Vicente Casillas, 35, was booked into jail after he allegedly assaulted a teen girl at a Chandler apartment complex pool. (Maricopa County, FOX 10 File Photo)

Chandler police have arrested a 35-year-old man accused of sexually assaulting a 16-year-old girl at an apartment complex swimming pool.

What we know:

Robert Mark Vicente Casillas was taken into custody Thursday morning at the luxury apartment complex near Price and Germann roads and booked into Maricopa County jail on a felony charge of sexual conduct with a minor. Investigators say the incident occurred on July 1, but formal reporting did not occur until the teenager and her family returned from a trip out of town, where they were attending a relative's funeral.

The backstory:

According to court documents, the victim was sunbathing on a float at the apartment pool when Casillas drifted toward her on his float and struck up a conversation. During the interaction, the teen explicitly told Casillas she was 16 years old. Police report that Casillas offered to apply sunscreen to her back before pulling her into a deeper section of the pool, grabbing her in a bear hug and sexually assaulting her.

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Investigators obtained pool surveillance footage that confirmed both people were together in the pool during the specified timeframe. On Aug. 18, detectives monitored a recorded phone call between the victim and Casillas, during which police say Casillas made incriminating admissions about touching the teen and apologized to her.

Dig deeper:

When Chandler police interviewed Casillas following his arrest on Aug. 20, he initially denied touching the teenager. However, after officers confronted him with details from the recorded call, court records state Casillas admitted that "obviously, it happened." Background checks reveal Casillas has an extensive criminal record in Arizona, including a prior arrest for smuggling illegal migrants and convictions for drug offenses, weapon violations and criminal damage.

What's next:

Casillas is currently being held on a $250,000 bond. His next court date is scheduled for Aug. 27.

Map of where the assault allegedly occurred:

The Source: Information in this report was gathered from the Chandler Police Department and Maricopa County Superior Court records.

ChandlerCrime and Public SafetyNews