Sandra Layne Case: First responders testify grandson never regained consiousness after shooting by grandmother

(CBS) DETROIT - Two police officers and a paramedic took the witness stand Thursday in the case of a 75-year-old West Bloomfield, Mich. grandmother charged with murder in the shooting death of her 17-year-old grandson last May, CBS Detroit reports.

Photos: Grandma accused of grandson's murder

The three testified that when they arrived at the scene on May 18, 2012, they heard gunshots coming from the West Bloomfield Township condo - and that the defendant, Sandra Layne, admitted she had just shot Jonathan Hoffman.

Derrick Hall, of the West Bloomfield Township Fire Department, testified that Hoffman never regained consciousness on his way to the hospital and they were never able to get his heart to beat on his own, the station reports.

Earlier in the trial, 911 tapes were played that depicted the teen begging for help while gunshots rang out in the background. At one point, Layne could be heard asking the dying teen if he wanted a glass of water, the station says.

An autopsy revealed Hoffman was shot three times in the chest, once in the abdomen and once in his left arm.

Defense attorney Jerome Sabbota argues that Layne was afraid of her grandson because of past incidents related to drugs.

Tests showed the teen had traces of synthetic marijuana in his body at the time of his death.

"She was upset, she was hanging on as best as a 75-year-old woman can," Sabbota said in reference to Layne's demeanor, according to the station.

He added that the grandmother, a retired teacher, plans to take the witness stand to testify in her own defense.

"The story will evolve when people that were present talk about it," Sabbota said.

Complete Coverage of Sandra Layne on Crimesider