Riverside police Sgt. Benjamin Shafer has been charged with two felony counts in connection with a Sept. 7 assault on a teenage boy in Lake Mathews.

Court documents show Shafer, 42, was arrested Dec. 11 on a warrant for assault of a person by means of force likely to produce great bodily injury and willful harm to a child.

Shafer was released from jail shortly after being booked and posting $35,000 bond.

He is scheduled to be arraigned in Riverside County Superior Court on Feb. 11.

Police Chief Sergio Diaz said Shafer was placed on administrative leave after the Riverside County District Attorney’s Office filed the charges Dec. 11. Also, Diaz said, an internal investigation has been launched related to the charges.

The charges were filed after a three-month investigation into the assault, charging documents show. That day, Shafer and the victim got into an altercation over a “minor accident” in the front yard of Shafer’s home, according to the documents.

The victim told authorities that Shafer “smacked him in the face, body slamming him onto the hood of a car, leg-sweeping him as he was running away, causing him to land on his head, and kicking him in the rib cage while he was on the ground and in the fetal position.”

The victim told authorities that the two went inside the home where Shafer “again assaulted him, hitting him, grabbing him by the neck and slamming him against a door frame, causing him to hit his head,” the documents say. “Shafer then physically threw him out of the house.”

The victim had a previous injury to his rib cage, which Shafer knew about, documents say. Having difficulty breathing, the victim was taken by ambulance to a hospital.

“A medical examination determined (the victim) did not suffer any rib fractures but the incident likely exacerbated his prior rib injury,” the documents said.

Riverside County sheriff’s deputies responded to the incident and launched an initial investigation, said Sheriff’s Department spokesman Deputy Michael Vasquez.

In an interview with deputies, Shafer said he “smacked” the victim and leg swept him “to prevent (the victim) from harming himself or Shafer while they were struggling during the incident and so the incident would end.”

Shafer denied kicking or punching the victim, assaulting him inside the house or slamming him onto the hood of the car.

Five people witnessed the incident in the front yard of the home, and one person witnessed the incident inside the home.

One of the witnesses, an adult male, called 911 after the victim complained he was having trouble breathing. That witnesses told authorities that “Shafer forcefully dropped into (the victim’s) side with his knee.”

The Sheriff’s Department turned the investigation over to the District Attorney’s Office in early October, said District Attorney’s spokesman John Hall. A warrant was requested for Shafer’s arrest Dec. 10, the day before he was booked into jail.

The Press-Enterprise does not generally identify victims of suspected child abuse.