Prosecutors and Napa County Sheriff's deputies are still working on three separate cases that resulted in fatalities this year.

Along with the death of an Angwin infant in a car, Mom may still face charges in baby's death, the drowning of a teen at Lake Berryessa and the shooting death of a man in Coombsville, several cases are lingering in the criminal justice system.

Berryessa tragedy

Sheriff's detectives are also still following-up and doing interviews in the Sept. 2 drowning death of 13-year-old Erin Brookman at Lake Berryessa. The teen, who died the day before her 14th birthday, was at the lake near the Pope Creek Bridge with family and friends, celebrating during the Labor Day weekend.

Brookman was in the water with a friend when she went under and did not resurface. Divers found her body the next day. An autopsy showed Brookman had a lethal level of carbon monoxide in her lungs from the boats' idling engines and a blood alcohol level of .17, more than twice the legal limit for adults in California.

So far, no arrests have been made in the case.

Sheriff's Lt. Jean Donaldson, who heads the department's investigation unit, said, "In the Lake Berryessa drowning, we are having trouble coordinating interviews with the people who were at the lake that day with the victim. They are not being very cooperative."

Donaldson said his office continues to interview witnesses.

Coombsville shooting

Sheriff's detectives also continue to work the case involving the June 18 shooting death of Stephan Williams, 64, at his Fourth Avenue home. Williams' ex-stepson Timothy Shane Martin, 37, was initially arrested and booked into the county jail for murder.

However, after reviewing the sheriff's investigators' reports, the district attorney determined there was not enough evidence to file a criminal complaint against Martin. The case was returned to sheriff's detectives for further follow-up.

Sheriff's Capt. John Robertson said earlier investigators believed the shooting could have been accidental.

This week, Donaldson said they are waiting for one more interview to determine if there is enough evidence to send the matter back to the district attorney's office for possible prosecution.

"If we go that direction, it will be up to the DA to decide if any charges will be filed against Mr. Martin," Donaldson said.