"Richard was one of the most generous people in the state," Shama said. "He would give me whatever I would ask for."
He said that Sharpe seemed like a "up-right, nice guy," not a potential murderer.
"I knew him over a period of years," he said. "I'm shocked to see that this has happened."
But other former HMS colleagues said that it was impossible to comment scientifically on Sharpe's psychology.
"It would be sexy to say 'Oh yes, he seemed strange,' or as every newspaper seems to find someone to say 'Oh, he was regular guy, I couldn't believe it.' ... I never expected he would kill anybody but what does that mean?" said Dr. Granstein, Sharpe's research supervisor in the Wellman Laboratory.
The Massachusetts Board of Medicine suspended Sharpe's medical license Wednesday.