Popular Professor Was on Cell Phone When He Was Ambushed by His Killer

New details obtained by ABC News make clear that nationally renowned law blogger and Florida State University professor Dan Markel was marked for murder at his Tallahassee home, but they deepen the mystery of who committed the crime and why.

An unnamed source told ABC that Markel was on a cell phone call while driving his Honda Accord back home on Friday morning. After pulling the car into the garage, he was followed in by an assailant who fired one shot at Markel's head through the car window, then left:

Markel was alive when cops arrived, with the keys in the ignition of his car, before being pronounced dead at the hospital hours later, police said. Markel was apparently on the phone at the time of the shooting, remarking to the person on the phone that someone was in the driveway, ABC News has learned.

These new details leave open the possibility that Markel was targeted either by a contract killer or by someone who knew him or his work. ABC News and other bloggers have focused on somewhat threatening comments Markel had received from readers of his popular PrawfsBlawg, but most were two years old and none seemed any more specific or ominous than the typical online fever-swamp fare.

Despite the revelation that there was a phone call in progress, the presence of a suspicious car—a silver or gray Toyota Prius—and the easy availability of Markel's phone, email, and teaching records, police still do not have a suspect or person of interest, leaving observers to speculate:

The new details reveal why police have classified Markel as the shooter's intended target, ABC News Chief Legal Affairs Anchor Dan Abrams said.

"Now we know why the authorities were so quick to say they believed this was a targeted killing and the neighbors don't need to worry," Abrams said.

The fact that a Prius was possibly being driven by the shooter was also notable, Abrams said.

"A Prius isn't a typical hit-man vehicle," he said. "[Was it] the person who wants to protect the environment and kill someone?"