GRAYSON — The judge in the Robert Drown murder, rape and arson case must now decide whether cell phone evidence linking the defendant to the three victims in the case is scientifically viable.

A hearing on that issue was Tuesday in Carter Circuit Court. The proceeding, known as a Daubert hearing, lasted about an hour and featured testimony from just one witness.

Said witness was an engineer with AT&T; Mobility who said his job was to select sites for cell phone towers. The man was not identified and his name was not entered into the court record. Commonwealth’s Attorney David Flatt said that was because of security concerns.

Kentucky State Police investigators have said they were able to tie Drown to the May 2009 murders of 31-year-old Jennifer Ison and her daughters Shannah, 10, and Marissa, 3, through his and Ison’s cell phone records.

Detective Jim Goble, the lead detective in the case, testified at an earlier hearing that a review of Jennifer Ison’s cell phone records showed that a series of calls between her and Drown had taken place the night before the victims’ bodies were found in their burned-out mobile home on Canoe Run, in the Hitchins area.

Also, according to Goble, police reviewed cell phone tower logs and found calls that placed him near the victims’ home the night of the slayings, even though he denied being in Carter County at the time the three were murdered.

Tuesday’s hearing featured mostly dry, highly technical testimony. Under questioning by Flatt, by Judge Rebecca Phillips and by Drown’s attorneys, Marcus Jones and Brian Hewlett, the engineer said that tying cell phone calls to the towers from which they originated was a fairly exact science.

He said that was due in large part to federal 911 mandates concerning mobile phones.

In response to a question from Jones, the engineer said that calls do occasionally bounce from one tower to another due to high call volume. But, he said that mostly happened in larger urban areas.

Also, even if a call did get bounced, the billing records still would show the tower from which it originated, he said.

After the engineer left the stand, Phillips said she would take his testimony under consideration and issue a ruling at a later date.

Still unresolved is the matter of exactly when Drown’s trial will get underway.

The trial was scheduled to begin May 5 in Johnson County, where it was moved due to pre-trial publicity. However, following a status hearing last week, Phillips said it was evident that defense attorneys were not going to be ready to go by then because their expert witnesses had not yet analyzed the arson and cell phone evidence in the case.

During that hearing, Phillips directed Jones to contact one of his experts and obtain from him a time frame for completing his work. On Monday, the judge was clearly upset when Jones informed her he had yet to do so.

“Mr. Jones, I need an estimate as to how long it’s going be,” she said. “Everything is on hold right now because we’re waiting on that time frame.”

Phillips ordered defense attorneys to file something in the court record no later than Friday showing how long it would take the expert to complete his analysis.

She scheduled another status conference for 1 p.m. May 12.

A new trial date for Drown hasn’t been set. However, Phillips said last week she had not given up on the possibility of the trial beginning sometime later this summer.

Drown could get the death penalty if he is convicted.