Tahjir Smith loved ice cream — no matter the time of day, no matter the occasion.

The 4-year-old was enthralled by cartoons, especially PAW Patrol, a Nickelodeon show about puppy first responders.

"He was always happy when he was around me," said his father, Mark Anthony Johnson. "He had a regular child's life."

Tahjir was smart, too, and obedient. On the rare occasion he misbehaved, Johnson said, Tahjir fessed up immediately.

On Jan. 22, Montgomery County authorities say, a stuttering Tahjir displayed that honesty when he told his mother he had spilled his breakfast cereal.

Later that day, in the back bedroom of a Willow Grove home, police say, the child was beaten to death by his mother, Lisa Smith, and her boyfriend, Keiff King, as punishment. According to charging documents, the couple struck Tahjir's head, torso, and bare buttocks with their hands and a shoe. When he became unresponsive, they placed him in the shower, underneath hot water, saying his punishment was not over.

Smith, 19, and King, 26, were arrested, accused of attempted first-degree murder, pending a coroner's report determining cause and manner of death. For the last two weeks, they have been held at the Montgomery County Correctional Facility.

Elsewhere, as family and friends prepared to bury Tahjir over the weekend, they grappled with a heart-wrenching question: How did this happen? 

Authorities noted shoe tread marks on the child's body and a burn near his shoulder. The coroner's initial exam found old rib fractures and a displaced rib, and Smith told authorities it was not the first time the couple had struck Tahjir, according to charging documents.

In King's past, there was at least one warning sign.

In 2016, he was arrested in Philadelphia for allegedly repeatedly punching a woman in the face while she was holding their 1-year-old son. According to court records, the charges were  dropped after the woman failed to appear in court. She did not return calls seeking comment. A spokesman for the Philadelphia District Attorney's Office declined to comment.

Philadelphia's Department of Human Services said it could not disclose whether Smith or King had been reported to or in contact with the agency, citing confidentiality laws.

In Montgomery County, the Office of Children and Youth Services said it had no reports of child abuse pertaining to either person.

Johnson, for his part, said he saw no signs his son was in harm's way.

"If anything was going on, they had him petrified," said Johnson, 21, of North Philadelphia. "He didn't say anything to me."

While Smith had custody of Tahjir, Johnson said he saw his son often, sometimes several times a week.

Johnson didn't know much about Smith's Willow Grove life, he said, or about King, her boyfriend of a year.

"It wasn't my business who he was," Johnson said. He had never been to the Lukens Avenue home where they lived with King's family.

From afar, the single-story home looks tidy. Bright blue shutters. Blue-and-white-patterned front door. Bikes in the driveway.

Upon closer examination, the drawn blinds were hanging crooked and torn. A couple of pieces of white siding lay on the front stoop. The mailbox was askew on its post.

Inside, authorities said, they found the home "deplorable" and roach-infested.

Knocks at the door there last week went unanswered. So did a note left for anyone who may still live there. At least one relative, King's 18-year-old cousin, Ishmael Powell, was in the home at the time of Tahjir's final beating, and told authorities he heard Tahjir crying and the sound of a hand hitting skin, according to charging documents.

Neighbor Stephen Lyles, who lived catty-corner to the couple, said the residents of that home kept to themselves. Until Tahjir's death,  he hadn't known who lived there.

On Jan. 23, Johnson left work at his construction job, took a shower, and was getting ready for bed when he received a text with a link to a news article.

Tahjir was dead, the article read.

At first, Johnson said, he thought it was some cruel joke.

After reading the details, he said, "I don't even remember too much." He called an Uber to Abington Hospital. But Tahjir was no longer there. The news articles came out a day after the boy's death.

"That was my guy," Johnson said. "I wish I had been around him more than I was."

Johnson, who met Smith when they were growing up in West Philadelphia, said he last saw Tahjir two weeks before he died. Recently, Tahjir had been splitting time between Willow Grove and his maternal aunt's house in Southwest Philadelphia.

Johnson described Lisa Smith as a quiet person, who was at times difficult to read. The two primarily communicated through Smith's sister.

Johnson said he had learned a few weeks ago that Smith was pregnant with King's child. Smith told authorities she was six months pregnant, according to charging documents.

In prison, King "was very upset that a young child lost his life," his attorney Jeremy-Evan Alva said.

Alva said he could not disclose details of their initial conversation, citing attorney-client privilege, and declined to discuss possible defense strategies. He said he did not yet know much about King, but he knew his client had young children of his own.

The Montgomery County Coroner's Office said it could not release any more findings until a final report is complete. King and Smith await preliminary hearings, which are set for Feb. 15.

Johnson said he had not decided whether he will attend future court appearances for Smith and King.

The message he has for her would not be fit to print.

"I've got something to say on a personal note," Johnson said, but "ain't no words going to bring my child back."