The remains of Riley Ann Sawyer _ weighing 12 pounds and stuffed into a plastic container _ remained unidentified for nearly a month after they were discovered October 2007. Investigators dubbed the child "Baby Grace."

Then Sheryl Sawyers of Mentor, Ohio, a Cleveland suburb, saw an artist's sketch and told Texas police she thought the child might be her missing granddaughter.

"I wish I hadn't been right," Sheryl Sawyers said Friday.

Riley's stepfather, Royce Clyde Zeigler II, was convicted of capital murder Friday and will receive an automatic life sentence without parole because prosecutors did not seek the death penalty. Jurors, who deliberated for 4 1/2 hours after an eight day trial, could have convicted Zeigler of a lesser charge of manslaughter.

Riley's mother, Kimberly Trenor, was convicted of capital murder in February and is serving a life sentence.

"The two people responsible for her murder have been convicted," Galveston County District Attorney Kurt Sistrunk said. "It's a good day for Riley."

Prosecutors said Zeigler and Trenor killed the toddler at their home in Spring, a suburb north of Houston, during a July 2007 discipline session intended to teach her proper manners. Zeigler was upset the 2-year-old didn't consistently use "please" and "thank you," authorities said.

Trenor and Zeigler beat Riley with belts, dunked her head in a cold bath water and threw her onto a tile floor, fracturing her skull, prosecutors said. An autopsy determined the child died of several skull fractures.

After Riley's death, the couple stuffed her body in a plastic box and hid it for months in a storage shed at their home. Then they drove about 75 miles southeast to Galveston Bay, where they dumped the container and body in October 2007, according to authorities.

Riley's remains were discovered by a fisherman on a small island in the bay.

"I wish it never had happened but I'm glad it's over and I'm glad we got the verdict we did," said Sheryl Sawyers, who had tears in her eyes. "I can try to move on."

Sistrunk said Riley's death "was a terrible crime that hit us all."

The impact of her death was still apparent Friday. One of the investigators in the case, Lt. Tommy Hansen of the Galveston County Sheriff's Department, took off his glasses and wiped away tears after the verdict was read. Another, Sgt. Mike Barry, pumped his left fist into the air in celebration.

Zeigler didn't react after the verdict was read. But his mother, Nellie Zeigler, slumped into one of the courtroom's padded benches in tears and repeated, "I just want to see him for a minute," after her son was taken away.

Dee McWilliams, one of Zeigler's attorneys, later said his client was "pretty devastated" by the verdict.

"From day one, we knew what we were up against ... how he had been demonized in the media. We did everything we could to change that," McWilliams said. "We are very disappointed in how things turned out."

Ziegler's attorneys told jurors their client was in another room when Riley died and there was no evidence he killed her.

But prosecutors said Zeigler lied repeatedly to investigators, giving them conflicting statements on the girl's death. Prosecutors showed the Galveston County jury video of Zeigler admitting dumping the child's body in the bay.

Trenor and Zeigler met playing an online video game and married in June 2007 after Trenor moved with her daughter from Ohio to live with Zeigler in his home in Spring.