Prince McLeod Rams had a history of fever-induced seizures, his mother said. But on the morning of Oct. 20, the 151 / 2-month-old was healthy, playful and happy, following her around the house and saying, “Mama, mama.”

Hera McLeod, who testified Monday in a Prince William County courtroom, said she got Prince ready for his fourth court-directed visit with his father. She packed up his favorite meal — McDonald’s oatmeal, milk and a sippy cup filled with apple juice — and dropped him with an intermediary.

By the next day, Prince was dead.

Prince William authorities allege that Prince’s father, Joaquin S. Rams, 40, drowned the boy. Rams had taken out more than $500,000 worth of life insurance on the toddler, according to court documents.

Rams has said that Prince suffered a seizure that afternoon and that he put the child in a tub of ice-cold water and splashed him to bring down a fever, according to authorities and court papers. His attorney, Timothy Olmstead, said Monday that Prince had been sick for some time and died as a result of his illness.

Juvenile and Domestic Relations Court Judge Paul F. Gluchowski ruled that there was enough evidence against Rams for a grand jury to consider the charge of first-degree murder.

During the hearing, Constance DiAngelo, a medical examiner, testified that water was found in Prince’s sinuses, lungs and intestines. She determined that he had drowned. DiAngelo also testified that she found bruises on his face, head, chest and back.

In his closing argument, Olmstead disputed the timeline of events and said that the medical examiner had not ruled on a key issue.

“It was likely an accident, if anything else,” he told the court.

Olmstead later said in an interview that the medical examiner ruled that the manner of death was undetermined. “She was not able to call this a homicide,” he said.

Prince had been the subject of a custody dispute in Montgomery County and normally saw his father on Saturdays.

McLeod said that two days before his final visit with his father, Prince had a seizure and bit his tongue so hard that it bled.

Before dropping him off that Saturday, she testified, she took him to a Harris Teeter and he spoke in a happy “babble” to a grocery store employee. She said he pulled at an Angry Birds balloon and made a “mess” by pulling down some plants.

That night, a 911 call was placed from Rams’s house. Prince was rushed to Prince William Hospital, and medical staff tried unsuccessfully to revive him, Andrea McKennon, an emergency room pediatrician, testified.

Blood was coming from Prince’s nose and he had a bruise on the left side of his forehead, she testified. “We were concerned about child abuse,” she said.

His mother later decided to take him off life support.

After the hearing, Olmstead said at a news conference that he could not go into all the details but that he would show that the boy’s illness, not his client, was to blame for his death. “That was the contributing factor in the boy’s death,” Olmstead said, referring to the seizures Rams reported. “He was very sick.”

DiAngelo, the medical examiner, called febrile seizures “benign,” and McKennon said it was rare for someone to die as a result of such a seizure.

McLeod said that as soon as she arrived at the hospital, she believed she knew what had happened.

“I don’t have any doubt in my mind,” she said during a news conference after the hearing. “I am proud that at the very least my son’s legacy will be to show that justice can work.”

A Prince William grand jury will decide in the coming weeks whether Rams should be indicted on the first-degree murder charge.