RALEIGH, N.C. — Investigators are facing a new twist in the investigation of Eric Miller's arsenic poisoning death. One of the people investigated in the probe apparently shot himself Monday evening.

Eric Miller, a Raleigh researcher, was poisoned to death last month. Arsenic residue was found in his widow's office at GlaxoSmithKline.

Police searched the lab and home of Derril Willard, one of the widow's co-workers, on Sunday. He was found dead Monday, apparently from a self-inflicted gunshot wound. Police say Miller's widow and Willard had some kind of relationship.

Investigators say Willard left a note in his home before he died. They will not reveal its contents, except to say it does have significance to the investigation.

The preliminary autopsy report confirms Willard died from a gunshot wound to the head. Officers say privately there is little chance the shooting was anything but suicide.

Willard likely shot himself sometime Monday morning after his wife left for work.