"How could you not indict? I don't understand," Schettino, 45, of Blue Point, said during a telephone interview. "I lost the most precious thing in the world to me. Today is exactly five months" since the crash.
District Attorney spokesman Robert Clifford said Monday that prosecutors had asked the grand jury to consider a felony charge of criminally negligent homicide against the deputy, Richard Tedesco, 37.
A deputy since 2007, Tedesco would have faced a maximum prison sentence of 4 years if he had been convicted on that charge.
Schettino said she learned of the decision Friday, through a hand-delivered letter from District Attorney Thomas Spota's office.
"The pain that goes through this family is unbearable," she said. "I'm so disgusted. I cry, I doze off, I wake up, I cry, I hug my daughter, I doze off."
Her son, William Schettino, 18, of Blue Point, was struck standing near his disabled car in the westbound HOV lane near Ronkonkoma, shortly before 6 p.m. on March 14.
Relatives said Schettino was on his way to night classes at the Brentwood campus of Suffolk County Community College.
Sheriff's Chief of Staff Michael Sharkey has said Tedesco was blinded by sun glare and was surprised by Schettino's stopped 2011 Mazda in the HOV lane. Tedesco had been driving in the HOV lane on routine patrol.
Sharkey said Tedesco had been removed from highway enforcement pending the outcome of the investigation but he was still serving "full duty" functions as a deputy.
Tedesco is "obviously very torn up about the whole situation," Sharkey said. "Both sides bear some pain. You can't compare the two. You obviously can't compare the loss of a child to what he's going through."
The grand jury hearing, which lasted more than five days, had testimony from 18 witnesses, including 12 eyewitnesses, a New York State Police accident reconstructionist and a Suffolk County crime analyst, Clifford said.
He said 32 exhibits were presented, including photographs of the scene and collision reconstruction documents. Clifford said prosecutors reached out to the Schettino family to submit a list of their own witnesses or any evidence they may have wanted the grand jury to consider but they didn't get a response.
The family's lawyer, Ted Rosenberg, of Holtsville, said that the prosecutor's office never reached out to him or the Schettinos to notify them of the grand jury hearing.
He said he filed a wrongful-death suit on behalf of the family in July against the county, the sheriff's department and Tedesco.
"The county is responsible because the deputy sheriff simply wasn't paying attention while he was driving down the expressway. He struck a parked vehicle in broad daylight while it was stopped and he should have seen," Rosenberg said. "If he had seen what was in front of him the tragedy could have been averted."