Little Shaemar Nelson-Thomas was less than a month away from celebrating his second birthday.

It was going to be a special milestone for the sweet-faced "Sponge Bob"-loving toddler and his loved ones. Thanks to recent rounds of physical therapy, Shaemar, who was autistic, had finally learned to crawl and inch his way up the steps in his grandmother's home.

With additional therapy, his family hoped that Shaemar would soon learn to talk.

But any chance they had to experience the joy of hearing the little boy speak was snuffed out Saturday night, police say, when Shaemar's father smothered him in the basement of his grandmother's Kingsessing rowhouse.

Troy Thomas, 25, was arrested Tuesday night and charged with his son's murder, said Homicide Sgt. Anthony McFadden. Thomas simply told detectives that "the baby just wasn't able to wake up," McFadden said. A medical examiner ruled that the toddler had died of asphyxiation.

"He was a sweet, adorable kid," said Minerva Nelson, 45, Shaemar's maternal grandmother. "He was always happy, and we were so thrilled to see how he was doing with therapy."

At 23 months, Shaemar enjoyed following his grandmother into the kitchen while she cooked. "He'd go to town on fried chicken wings," she said. "He was always smiling."

Nelson said she was in her home on 50th Street near Upsal Saturday and Thomas was in the basement with Shaemar and the baby's mother, Tuesday Nelson, 24.

She said Thomas quietly walked up the basement steps shortly after 8 p.m. "He said Tuesday wanted me to come downstairs right now, that it was an emergency."

"I went down the steps and the baby was just laying there. Tuesday was changing his Pampers. I started to do CPR, and then we brought him upstairs, I laid him on the couch and continued the CPR.

"My brother called 911, but it was too late. He was already gone," Nelson said.

Thomas remained silent during the ordeal, Nelson said. "He didn't say anything. He acted like he didn't have any feelings, like he didn't care.

"He killed his baby and he had no remorse."

On Sunday, officials from the Department of Human Services arrived at Nelson's home and temporarily removed Shaemar's three older siblings: a 3-year-old boy, and 4-year-old twins.

Sources close to the investigation said DHS became involved with Shaemar's family five years ago, after allegations of abuse and neglect concerning his four siblings.

At least one allegation proved to be true, sources said, and as a result, three siblings were placed in Minerva Nelson's care.

A fourth child, a 5-year-old girl, was placed with another grandmother and remains in her care.

"We made a mistake by letting Troy be around here, but I hope they [DHS] don't make the other kids suffer for it," Nelson said.

She characterized Thomas as a lay-about father who wanted little to do with his son.

"He was just there to play video games," Nelson said. "I tried to get him involved in Shaemar's life, but he was only interested in X-Box or PlayStation." *