Tashia Seneca went into her 3-year-old son’s bedroom Tuesday morning, expecting to find him fast asleep in his little play tent. Instead, she realized he wasn’t breathing.

Investigators say his death was no accident.

Her live-in boyfriend, Justin Crouse, 30, of Salamanca, had awakened in Seneca’s home on Sulphur Springs Road on the Cattaraugus Indian Reservation at about 1 a.m. Tuesday to find his girlfriend’s 3-year-old son, Gage Seneca, out of his bedroom and walking around the living room.

The 6-foot-2, 210-pound construction worker struck the child and then picked him up and put him back in the play tent in which the boy had been sleeping since making the transition from a crib a couple of weeks earlier, according to Erie County Sheriff Timothy B. Howard.

“Mr. Crouse,” Howard said, “went back to bed.”

Tashia Seneca, who has two other children, had slept overnight with her 6-year-old daughter in the girl’s room. At about 8 a.m., she went into Gage’s room to retrieve a toy.

When she realized that Gage wasn’t breathing, she called 911. Her mother, an emergency medical technician who also lives at the home, began performing CPR.

The reservation’s volunteer firefighters arrived, and the boy was rushed to Lake Shore Hospital in Irving, but there was nothing anyone could do.

“It was clear to [the emergency responders] the child had been deceased for some time,” Howard told reporters Wednesday.

The boy was pronounced dead at 8:45 a.m. An autopsy performed later Tuesday found that Gage died as the result of blunt-force trauma to the head.

Detectives called Crouse, an unemployed construction worker, who agreed to come to the Sheriff’s Office’s station in North Collins for questioning. He was arrested early Wednesday on a charge of second-degree murder and later arraigned in Brant Town Court.

If Crouse is convicted as charged, he could face 25 years to life in prison, Erie County District Attorney Frank A. Sedita III said.

Investigators do not know whether Gage was already dead when Crouse allegedly put him back in his tent or whether the boy could have been saved if he had been taken to a hospital after being injured, Howard said at a Wednesday news conference.

Investigators found no history of child abuse or neglect at the home, which detectives said was immaculate and filled with children’s toys.

There had been a few 911 calls from the house over the last five years, including one for a suspected domestic dispute that did not involve Crouse and was not violent in nature, Howard said.

Crouse has nine arrests on his record, all misdemeanors, mostly for disorderly conduct and criminal mischief but no felonies, according to the Sheriff’s Office.

“No prior arrests for violent crimes,” Howard said.

Tashia Seneca had three children: Gage, the 6-year-old daughter and a 4-year-old son. She works at the Seneca Allegany Casino.

Investigators learned that Crouse got along well with the 4-year-old and had taken him out on Monday.

Crouse wasn’t as close to Gage, Howard said, but there was no indication he had ever abused the boy.

Seneca and Crouse had been dating for about seven months, and he was living with her part of the time and in Salamanca the rest of the time, Howard said. Although the relationship had been “dwindling” recently, the sheriff said, “there were no indications of any kind of domestic violence.”

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