A Rockwall memory care worker faces four first-degree felony charges after the Rockwall Police Department says he sexually assaulted a 67-year-old dementia patient at two local facilities over a 10-day span.

Zachary Daylon Yoakum, 24, was arrested Saturday, Aug. 15, and booked into the Rockwall County Jail on four counts of aggravated sexual assault, according to the Rockwall County Herald-Banner, citing an arrest affidavit. His bond was set at $400,000.

The alleged assaults took place between Aug. 1 and Aug. 10 at Village Green Memory Care Community Center, where Yoakum worked, and at Rock Ridge Assisted Living & Memory Care, where the woman was later transferred. Both facilities are in Rockwall.

Three of the four alleged incidents occurred at Village Green. The fourth happened after the woman moved to Rock Ridge on Monday, Aug. 10.

How the investigation began

The woman had been hospitalized in July after experiencing psychosis and was subsequently diagnosed with dementia. After her discharge, she was placed at Village Green.

Her daughter contacted authorities after finding text messages and phone call records between her mother and Yoakum. The woman told her daughter they were not in a relationship.

After the woman was transferred to Rock Ridge on Aug. 10, a facility employee called her daughter the following day. A young man had tried twice to visit her mother, according to the affidavit.

What the affidavit describes

During a police interview, the woman said Yoakum told her he loved her and wanted to marry her. She told investigators he gave her code words intended to keep their relationship secret.

The woman was unable to provide specific dates for the alleged assaults because of her dementia, the affidavit states. She acknowledged having sexual activity with Yoakum four times.

In one alleged incident, Yoakum put his hands down the woman's pants while the two were in a public garden at a memory care facility.

A sexual assault examination was conducted, but the affidavit does not include the results.

What the charges carry

Under Texas law, aggravated sexual assault is elevated to a first-degree felony when the victim is elderly or disabled. The charge carries 5 to 99 years or life in prison, requires lifetime sex-offender registration upon conviction, and a judge cannot grant probation after a guilty verdict.

The woman's name was not released. A pseudonym is used for her in the arrest affidavit.

The allegations have not been proven in court. Yoakum is presumed innocent unless proven guilty.

No court date has been announced. Neither Village Green Memory Care Community Center nor Rock Ridge Assisted Living & Memory Care has issued a public statement about the case.