Rory Kennedy, Kerry's younger sister, said her sister has a reputation for being sober and healthy. She said the two sisters, nine years apart, have a "very close relationship."
"She's really my best friend," Rory Kennedy said under oath.
One witness, neighbor Emily Liebert, testified today that Kennedy asked her to go to Kennedy's home the night of her arrest and count her sleep pills and thyroid pills out of concern she had either mixed up her medication or had a seizure.
Meanwhile, Kennedy has sat at the defense table, at times fingering rosary beads as others have testified. Earlier this week, she was photographed pushing her mother, Ethel Kennedy, in a wheelchair into and out of court.
The prosecution alleges that Kennedy chose to drive while under the effects of the sleep medication, saying that if she truly did take the medicine accidentally, she should have pulled over when she felt it beginning to affect her. Instead she continued to drive for five miles before the crash.
A toxicologist the prosecution called to testify, however, said that the medicine can work quickly, and begin to affect someone within 15 minutes.
"People start to have effects in 15 minutes to a half hour" after taking it, said Elizabeth Spratt of the Westchester County Department of Labs.