Investigators have discovered new evidence in connection with the January stabbing death of a 16-year-old girl whose body was found beside a road in downstate Putnam County.

The Putnam County Sheriff’s Office conducted a search Wednesday at the Color Point greenhouse facility in downstate Granville, according to a statement from the sheriff’s office.

The search turned up a weapon that investigators believe is associated with the Diamond Bradley case, the sheriff’s office said. The weapon was being analyzed by the Illinois State Police Crime Scene Service Lab.

Putnam County, Diamond Bradley, Missing Girl, Met over the interenet

Richard A. Henderson | Putnam County Sheriff’s Office

Richard A. Henderson, of Standard, was charged in February with concealment of a homicidal death in connection with the case, according to the sheriff’s office. Henderson previously worked at Color Point and investigators conducted the search after learning he may have discarded evidence there.

Bradley was found about 1 p.m. Jan. 27 in a ditch alongside County Highway 850 North in Granville Township, the sheriff’s office said. She had been stabbed multiple times and her death was ruled a homicide.

Henderson met Bradley on the internet and the two agreed to meet the morning of Jan. 24. Henderson picked Bradley up near her home in Spring Valley and drove her into Putnam County. At some point, Henderson stabbed Bradley to death, authorities said.

Henderson was linked to Bradley through an investigation that included tracking Bradley’s cellphone and the use of surveillance cameras, the sheriff’s office said. Nearly 20 law enforcement agencies worked on the case.

The case was still under investigation and authorities said they expected to add more charges against Henderson later.