Nearly 15 years after Michelle Parker disappeared, Orlando police say newly analyzed cellphone records helped lead to the arrest of Dale Smith, 55, in connection with her murder.

Smith was arrested Oct. 14. He has entered a plea of not guilty to a second-degree murder charge.

Parker, an Orlando mother, vanished in 2011 — hours after she and Smith appeared on the TV program The People’s Court. Her body has not been found.

According to an arrest affidavit, detectives this year reviewed the original cellular data records obtained in 2011 and discovered additional data that had not been analyzed.

“It is likely this data was not readable to detectives in 2011,” the report stated, “This data revealed more precise location and user data, to include messages, for the suspect’s and victims’ phones.”

[WATCH: Discrepancies, phone data led to Dale Smith’s arrest in Michelle Parker case, new documents show]

Smith told investigators Parker only stayed at his home for 10 minutes after dropping off the children, court records said. However, those records state, cellphone records show Parker’s phone was at Smith’s home for more than an hour.

Those cellphone records, analyzed by the FBI, show both Parker and Smith’s cellphones left the area and traveled to Belle Isle, which police said contradicts Smith’s statements. Smith’s phone then appeared headed toward his parents’ home, but Parker’s stayed near Lake Conway, where detectives said they found it submerged underwater.

FBI analysis, “confirms the suspect and victim’s phone together at the suspect’s home and then traveling toward the suspect’s parents’ home,” according to the affidavit.

So how can investigators pinpoint a phone’s exact location? One expert says it’s not about the cell tower itself — it’s about the antennas on top of it.

“The network doesn’t work like we all think,” said Andrew Garrett, CEO of Garrett Discovery, an Orlando-based digital forensics company.

Garrett told News 6 he and his team use the same equipment as the FBI to analyze cellphone data and testify in court cases.

“We can tell you exactly where that cell tower broadcast to, and based on that, we could possibly build a pattern of life. The defendant went from one area to the next because those two cell antennas don’t have overlapping coverage. We know they had to travel from this area to this area,” Garrett said.

[WATCH: Who is Dale Smith? Orlando police arrest ex-fiancé to missing woman Michelle Parker]

According to Garrett, the only way to map a carrier’s real coverage is drive-testing with specialized equipment, and unlike GPS, network data shows only a broad coverage area rather than a precise point.

Garrett Discovery uses what they call a scanner to look at cell coverage to see if a phone can even connect to a given antenna.

“The system you’re looking at is collecting 10,000 measurements a second,” Garrett said.

After collecting the data, analysts build a map to show the actual cell coverage.

“It will create either green dots or red dots or yellow dots on screen to tell us, yes you can make a phone call, no, you cannot make a phone call,” Garrett said.

Garrett also notes proximity to an antenna does not determine which one a phone connects to. A phone connects to the antenna with the strongest signal— not necessarily the nearest one. If there’s an obstruction, such as a tree or building, a phone may connect to an antenna that’s farther way.

Signal frequency also plays a key role — and it matters in court. Lower frequencies can travel farther and cover larger areas, while higher frequencies cover shorter distances.

The “difference between 700 megahertz and 3,400 megahertz. What you’re really talking about the differences between 28 miles and four miles,” Garrett said, “So if the defendant was using a high-frequency antenna at the time of the crime, we could say the defendant is within a four-mile range. And if the crime scene is in that four-mile range of the cell tower, then we could say they’re within four miles of the crime scene. But if they’re using a low-frequency antenna, the best we can say is the defendant is somewhere within a 28-mile circle.”