A prominent research scientist accused of injecting a cancer-causing agent into a colleague's nasal spray recently brandished a pistol at work and kept a text called "The Poisoner's Handbook" at his office, officials said.

John G. Linner, 47, of The Woodlands is jailed without bond for allegedly plotting the death of W. Barry Van Winkle, his associate at the Cryobiology Research Center in The Woodlands, north of Houston.Linner was director of the center, an affiliate of the University of Texas Health Science Center at Houston. The university recently decided to shut down the lab and Linner apparently was jealous that Van Winkle already had secured a new position with UT's medical school in Houston, officials said.

The 6-foot-5, 300-pound Linner reportedly was characterized by some co-workers as a "mad scientist" so consumed by a love for science that he applied laboratory techniques to his favorite pasttime, making chili.

"The Poisoner's Handbook" and several others found in Linner's home and office reveal how to use poisons to cause slow deaths, the Houston Chronicle reported Friday.

Linner's wife of two years said the scientist is not capable of attempted murder.

"John did not do this," Linda Linner said. "He's a very kind and sensitive man."

Linner's attorney, Robert C. Bennett, said the scientist also maintains his innocence.

"He told me, `I have no motive, I have no reason. I didn't do that,' and denies it strenuously," Bennett said.