CHICAGO (CBS) — Lake County Sheriff’s Police say undercover officers were able to get evidence that led to the arrest of a documented gang member on drug and gun charges.

Lake County Sheriff Mark Curran said 23-year-old Travaris Knox sold crack cocaine to an undercover officer in the Gang Task Force, and hinted he had guns for sale, too.

But the sheriff said, during the undercover gun sale, Knox suspected he was dealing with a police officer, got nervous and did not complete the sale.

“We had enough information based on the prior cocaine sale to get a warrant for Mr. Knox’s person and his residence. We executed a warrant on him. We found the firearm on him,” Curran said.

Besides drug charges, Sheriff Curran said the documented gang member has been charged with unlawful use of a weapon by a gang member, unlawful use of a gun by a felon, and possession of a defaced firearm.

Knox is being held on $100,000 dollars bond at the Lake County Jail. His next court date is Oct. 31.