GENESEO, N.Y. -- The driver of a tractor-trailer that crashed last week on Interstate 390 was on heroin, according to deputies in Livingston County.

Robert Shenk, 56 of Rockingham, Virginia was behind the wheel when the 18-wheeler swerved off the road Thursday in the town of Geneseo, crashing into the highway's median. The truck was carrying a load of beer kegs and cases of beer, heading north.

Other drivers called 911 and said the truck was swerving across lanes in the moments before the crash.

Deputies found heroin, hypodermic needles and other drug paraphernalia, and in the truck's cab, a puppy, which was not hurt.

Shenk was taken to a Rochester hospital with injuries described as minor, There, a deputy trained to recognize signs of drug abuse determined Shenk was "under the influence of a central nervous system stimulant and narcotic analgesic" and that Shenk was unable to drive safely.

Shenk is charged with DWAI, criminal possession of a controlled substance, and also faces several traffic violations.