Defendant Claims He Didn't Mean To Hit Former Boss During 2016 Chappaqua Shooting

CHAPPAQUA, N.Y. (CBSNewYork) -- A bizarre defense theory has been used in a Westchester trial.

As CBS2's Brian Conybeare reported, the man accused of shooting his former boss admitted he fired a gun in Chappaqua last summer, but his attorney said it was only to get media attention.

Unemployed medical researcher Hengjun Chao is on trial for the August 2016, shotgun shooting of Dr. Dennis Charney -- his former boss at the Mount Sinai School of Medicine.

Chao called 911 himself while outside of Lange's Deli on King Street in Chappaqua.

"The defendant pulled the trigger," prosecuting attorney Daniel Flecha said.

Westchester County prosecutors said the 50-year-old native of China drove a red Toyota from his home in Tuckahoe to ambush Charney as the doctor picked up his usual buttered bagel and iced coffee at the deli, leaving the front door full of holes.

Prosecutors said the motive was revenge for Charney firing Chao in 2010 over misuse of research data.

"With one pull of the trigger Chao unleashed years of frustration," prosecuting attorney Daniel Flecha said.

But defense attorney Stewart Orden has a much different theory.

"He went there to fire a gun, not even to injure, to fire a gun in the direction of a man he holds responsible for the deaths of teenagers, and get arrested, and tell you his story," Orden said.

Their claim; that the shooting was the only way Chao could expose what his lawyer called, 'large scale fraud and manipulation of data.'

They allege the fraud involved Charney's past research on an anti-depressant that was later linked to increased suicide in teens.

Mount Sinai issued a statement blasting the argument.

"The baseless claims made by the defense in an effort to justify a criminal act by the defendant is offensive and disgraceful."

On Tuesday, the jury saw the shotgun used in the crime, and heard from expert witnesses.

On Wednesday, the victim is scheduled to take the stand.