BRENTWOOD — An Epping woman is accused of repeatedly beating an 18-month-old child with the force of a high-speed car crash, likely causing him permanent eye damage.

As the result of an ongoing Epping Police investigation, Tina Castine, 27, of 97A Jenness Road, was arrested this month on three felony assault charges and seven misdemeanor child endangerment charges.

Police allege Castine assaulted the child on numerous occasions while she was caring for him at her home, and selling drugs while children were present in her home.

Castine’s father, Timothy Castine, 56, with whom she was living at the time, was also arrested for allegedly falsifying evidence. Police claim that he deleted a cell phone video taken by a witness that showed Castine abusing the child.

According to police affidavits, the investigation began on April 8 when police, along with EMTs, were dispatched to the Castine home to investigate a report of a three-year-old child seizing and becoming unconscious.

Police found that the child was actually 18-months old, and on the ambulance ride saw that he had bruising on both sides of his forehead and swelling above his ear, according to the affidavit. At Exeter Hospital, it was found that there was a brain abnormality and the child was eventually brought to Boston Children’s Hospital because of the severity of his injuries.

Doctors at Boston Children’s found that the child had bleeding on both sides of the brain as well as two partially detached retinas. According to police, the child is expected to have permanent vision impairment.

The day after the ambulance call, Jami Castine was interviewed by police, telling them that in addition to her three children, she had been watching a friend Lindsay Dubon-Romero’s children since March. Castine told police that any injury to the hospitalized child’s head was likely caused by his older sibling pushing him down.

However, that same day, doctors at Boston Children’s told police that the child’s injuries were likely caused by abuse, comparing the force of the injuries to falling out of a second floor window onto concrete or being involved in a car crash while driving more than 80 miles per hour.

During additional witness interviews, police said that Castine’s mother, Joni, told them she had recently watched the children and noticed that the now-hospitalized child could not open his mouth and she had to force it open to feed him with a “sippy cup.”

“The kid had a brain injury,” Castine’s mother said, also adding that her daughter should not be in charge of children, according to police.

According to affidavits, additional witnesses interviewed on April 11 came to the station voluntarily out of concern for the children’s well-being and told police that Castine would use racial slurs and sexual vulgarisms to refer to the children.

According to witness statements, on one occasion, Castine dangled the infant by one arm then slammed him down into his crib.

Dubon-Romero told police that both her children were in good health when she first dropped them off at the Castine residence and had never been hospitalized for injuries before. Castine would occasionally contact her to say that the children had fell down and been bruised, but it wasn’t serious.

On April 20, Dubon-Romero’s older child was examined at Elliot Pediatrics, where it was determined that he had also sustained bruising to his body consistent with abuse.

A friend of Castine later told police that on April 8, she witnessed Castine kicking Dubon-Romero’s child in the back of the legs, making him fall over, and recorded the incident on her cell phone. According to the affidavit, the woman said she had seen Castine hit and kick both of Dubon-Romero’s children.

According to the woman, Timothy Castine took the phone from her after learning about the recording and deleted the video. Joni Castine admitted during interviews with police that her husband was “very protective” of their daughter.

According to the affidavit, after analyzing Jami Castine's cell phone, police found text messages and photos indicating that she had been selling marijuana out of her home while watching the children.

Jami Castine offered no pleas to the three felonies and pleaded not guilty to all misdemeanors at her arraignment in Brentwood District Court, and waived a probable cause hearing. She is free on $10,000 cash bail. Timothy Castine is free on $3,000 personal recognizance and $7,000 cash bail.

Both will next appear in Rockingham Superior Court, though dates were not yet available Monday.