Riley Ann Sawyers was born March 11, 2005, and was two years old at the time of her death. She was the daughter of Robert Thomas Sawyers and Kimberly Dawn Trenor, who had met as students at Mentor High School in Ohio. After her parents separated, Trenor moved with Riley Ann to Spring, Texas, in May 2007 and married Royce Clyde Zeigler Jr. on June 1, 2007. Zeigler believed in strict discipline, including corporal punishment, and both he and Trenor administered beatings to the child.
According to a videotaped confession and signed affidavit from Trenor, on July 24, 2007, she and Zeigler beat Riley Ann with two leather belts and held her head underwater in a bathtub. Trenor stated that Zeigler picked the child up by her hair and threw her, causing her head to strike the tile floor, after which Riley Ann could no longer stand. Trenor described the death as accidental, calling it "a case of discipline that went too far." After the child died, the couple purchased a plastic storage container, wrapped the body in garbage bags, stored the container in a shed for about two months, and then dumped it into Galveston Bay from a bridge near the Galveston Causeway. Trenor also forged documents falsely claiming Riley Ann had been removed from their custody due to alleged sexual abuse.
A fisherman discovered the body in Galveston Bay on October 29, 2007. A coroner found three skull fractures, and the case was investigated as a homicide. Because the remains were unidentifiable, forensic artist Lois Gibson created a composite sketch, and the unidentified child became known publicly as "Baby Grace." Riley Ann's paternal grandmother, Sheryl Sawyers, recognized the sketch online and alerted authorities; DNA testing confirmed the identification on November 30, 2007.
Following their arrests, Trenor and Zeigler were each held on $350,000 bond and initially charged with injury to a child and tampering with evidence. Zeigler attempted suicide before Thanksgiving 2007, leaving a note stating his wife was innocent, but later claimed at trial he was in another room when Riley Ann died. Trenor's trial was delayed due to her pregnancy and resumed after she gave birth in January 2009. She was convicted of capital murder on February 2, 2009, after a 90-minute jury deliberation, and sentenced to life without parole; she is incarcerated at the Mountain View Unit in Gatesville, Texas. Zeigler was convicted of capital murder and evidence tampering on November 6, 2009, following four-and-a-half hours of jury deliberation, and received an automatic life sentence without parole because prosecutors did not seek the death penalty; he is incarcerated at the Wallace Pack Unit near Navasota, Texas.
Riley Ann's cremated remains were returned to her family in Ohio in January 2008 and interred at Mentor Municipal Cemetery. The Hitchcock City Commission in Texas later named "Riley's Island" in her memory in March 2008.