State police arrested an 18-year-old Eastern Shore man Thursday and charged him in a robbery Feb. 28 at an Eldersburg veterinary hospital.
Investigators said they believe two other suspects have fled the state and that arrest warrants will be obtained.
Adrian J. Rhyanes of Centreville was arrested about 2 p.m. at his home and taken to the Centreville barracks for transport to Westminster. He was held at the Carroll County Detention Center on $100,000 bond on multiple robbery-related charges.
Officers said three teen-agers, one carrying an Uzi-type automatic assault weapon, burst into the Carrolltown Veterinary Hospital about 2 p.m. Feb. 28 and demanded cash and drugs.
All four employees were forced to lie on the floor after one was taken to the prescription drug cabinet in a rear room, police said.
The intruders took 15 bottles of ketamine, a cat tranquilizer similar to phencyclidine, or PCP, that is commonly known as "special K" among teen-agers who frequent "rave" dance clubs, police said.
Officers said ketamine is a liquid, but it can be converted to a powder form and snorted or smoked.
Investigators said one of the youths entered the hospital office in the 1800 block of Liberty Road about 15 minutes before the robbery and asked about neutering an animal, then asked to use the bathroom.
The next day, investigators received an anonymous telephone call with information on the robbers.
When officers went to Mount Airy to check on the information, they got a description of the youths and a video from a security camera at a gasoline station, police said.
Mr. Rhyanes was arrested as a result of that information, police said.