The anonymous call that sent police to Adnan Syed — and the cell tower data that wouldn't hold

January 13, 1999, was a school day, and Hae Min Lee left Woodlawn High School at the end of it.

She was 18, a senior, and she did not come home.

Her body was found on February 9, 1999, in Leakin Park in Baltimore.

The cause of death was manual strangulation.

For weeks, the case went unsolved.

Then the police received an anonymous phone call.

That call steered the investigation toward Lee's ex-boyfriend, Adnan Syed.

The tip is documented in the record.

The caller's identity is not.

The exact content of the call is not established either.

Who was on the other end of that line?

What did they say, and why did they wait?

Why did it take weeks for the police to act on it?

That would require evidence.

At the time, the anonymous call was enough to shift the focus.

It was a fact, but a thin one.

It is a fact that the call was made.

It is not a fact who made it.

The record leaves that open, and it has stayed open.

THE CELL TOWER RECORDS

The case leaned on the cell phone records.

Those records placed Syed in the Leakin Park area around the time of the murder, the prosecution said.

The defense argued the technology could not be trusted.

Incoming calls, the defense said, could have been routed to a tower far from the phone's actual location.

A tower ping is not a pinpoint.

It is a region, a radius, a guess dressed in a timestamp.

The lead detective presented the records at trial as if they were a map with an X.

The phone was near the park, he testified.

The phone was near the park, the prosecution repeated.

But the phone was in Syed's car, and the car was not the body, and the body was not the phone.

No physical evidence linked Syed to the crime scene.

No fingerprints.

No DNA.

No witness who saw him near Leakin Park that afternoon.

The record shows the tower data was central to the case.

The record also shows the defense attacked it, and the attack was not answered with science.

Whether the cell tower data actually placed Syed at the murder scene at the exact time is contested and not definitively established.

That is what the record says.

It is what the record does not say that built the doubt.

The tower could have been wrong.

The call could have come from anywhere.

The case could have been built on a signal that meant less than it appeared.