The victim was pretty new to Eastwood Academy on Houston's east side four years ago when she says the attacks happened. But now, she's pressing charges.
"Calvin Williams has been charged with two counts of sexual assault of a child that occurred back in 2007," explained Denise Oncken with the Harris County District Attorney's Office.
Williams was the campus security officer at the HISD charter high school. He told prosecutors that the victim used to read her poetry to him, and the girl told investigators she became good friends with Williams.
It was at 72nd Street and Harrisburg on January 15, 2007, that the victim says the first attack happened, telling investigators Williams parked his silver Dodge pickup truck at an abandoned car wash and the pair engaged in a sex act.
Two weeks later, on January 27, the victim says Williams took her to a movie theatre on the west side of town and it was there she says that Williams sexually assaulted her again.
It wasn't until February 2011 that the victim made an outcry, sparking the investigation. HISD suspended Williams with pay in February. He was relieved of duty and resigned after he was charged with the two felony counts Monday.
Prosecutors say a delayed outcry is not unusual in sex crimes cases.
"Delayed outcry is very common and she outcried approximately four years after the fact," Oncken said.
Williams is due in court Wednesday. If he's convicted, he faces two to 20 years in prison on both counts.