Investigators are trying to figure out what caused a distraught and blood-covered James Island man to ram a tractor trailer rig into a police cruiser and two other cars in a bizarre episode Friday that left two people injured along Folly Road, authorities said.

Richard G. Summers, 53, of 1105 Blue Marlin Drive, was being held at the Charleston County jail late Saturday on three counts of assault and battery with intent to kill and a variety of traffic and property offenses, including reckless driving and hit-and-run involving great bodily injury, authorities said. His bail is set at $350,000, according to court records.

The incident started when Summers pulled up next to a sheriff's deputy at Folly and Camp roads around 9:15 p.m. Summers, dressed in his underwear and covered in blood, told the deputy someone was trying to kill his son and then took off running through a convenience store parking lot, Sheriff's Maj. John Clark said.

The deputy and a nearby Charleston police officer ended up with a physical confrontation with Summers when they tried to speak with him, Clark said. He got away, climbed back in the rig and rammed it into the rear of the deputy's cruiser, demolishing the car, he said.

The rig rammed a second vehicle and then a third, tipping over a Jeep Cherokee with two people inside, Clark said. The rig raced down Folly Road to a Burger King, where the driver tried to squeeze through the drive-thru before slamming into a Dumpster, he said.

Summers was transported to a hospital, but doctors determined he wasn't injured, Clark said. Investigators aren't sure how he ended up so bloody or where the blood came from, he said.

Deputies went to Summers' home, where they learned he had been involved in some sort of family incident earlier in the day, Clark said. Neither his wife nor his son were injured or in jeopardy, he said.

Clark had no information on the identities of the two people injured in the Cherokee. He said their injuries did not appear to be life-threatening.

Reach Glenn Smith at 937-5556 or gsmith@postandcourier.com.