HAVERHILL (CBS) — A man driving a school van was arrested in Haverhill Thursday after police said he was under the influence of drugs while driving a student. Shawn McCarthy, 48, of Exeter, N.H. appeared “very lethargic” when police responded to a River Street parking lot around 5:30 p.m.

Police “observed extensive damage to the right front passenger side door, mirror and the front right tire was falling off the rim,” according to documents, but McCarthy was “unaware that he was involved in an accident.”

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The 13-year-old on board told police, McCarthy was “changing lanes in an erratic manner,” and hit a sign “before side swiping a guard rail on the right side of the van.” The student begged him to stop and finally, he pulled over. Then the student used his cell phone to call their parents, police said.

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They were taken to Merrimack Valley Hospital for shoulder and knee pain.

During the investigation, officers found “several peach colored pills in the door pocket” of the van.

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McCarthy is charged with operating under the influence of liquor, negligent operation of a motor vehicle, reckless endangerment of a child, and possession of a class E drug.