While under the influence
The State must prove that the defendant was impaired by either alcohol, drugs, or a combination of both.
“In the instant case, there was sufficient direct evidence establishing the elements of DUI and the identity of the perpetrator, such that the circumstantial evidence was merely corroborative. In South Carolina, the corpus delicti of DUI must be established by proof that a person's ability to drive has been materially and appreciably impaired by the use of alcohol and/or drugs. In other words, the State has to prove: (1) Salisbury's ability to drive was materially and appreciably impaired; and (2) this impairment was caused by the use of drugs or alcohol.” State v. Salisbury, 343 S.C. 520, 524 (2001) (citations omitted)