The Pleasanton teen who ran down and killed a bicyclist on Foothill Road on June 9 had his charges elevated to murder and was taken into custody in court Wednesday morning.

Cody Matthew Hall, 18, was led out of court in handcuffs after Superior Court Judge Hugh Walker ordered him held without bond. The murder charge was added by the District Attorney's Office, replacing an initial charge of vehicular homicide. Hall did not enter a plea.

The teen driver was charged in the death of Diana Hersevoort, 58; he still faces a charge of reckless driving causing bodily injury for striking her husband, Joe Hersevoort, who suffered a broken leg.

The Dublin woman was killed in the crash near Golden Eagle Way that occurred around 1 p.m. The police report said Diana Hersevoort was thrown from her bicycle and pronounced dead at the scene.

Hall, who graduated from Foothill High in June, faces 15 years to life on the murder charge and an additional three years and eight months for the reckless driving charge, according to Alin Cintean, a former Sacramento County prosecutor now in private practice.

"He would have the possibility of parole," Cintean said. He said he was surprised that the murder charge was added, calling it "very rare."

"In order to add murder charges, they would have to show some type of intent to kill," he said. "It would indicate they would try to prove the intent by implication."

Cintean compared the addition of the charge to someone who kills another while driving drunk after having been previously convicted of DUI.

"If they're drunk and they kill someone, the intent is implied," he said, adding the prosecution must have "strong evidence" that Hall knew his behavior could cause death.

Cintean didn't think that social media posts by Hall, asking others to go on a "death ride," would be strong enough.

"I doubt that a jury would find that's intent to kill. There must be other evidence surrounding that (charge)," Cintean said. "The defense would argue that a death ride could be just a scary ride or just a very fast drive."

He said, however, if Hall had prior convictions for moving violations that might be enough to warrant the more serious charge.

Cintean said that the murder charge could give the prosecution "a certain amount of leverage to avoid a possible life sentence."

"That happens a lot," he said. "Ethically they would have to prove (the charge) beyond a reasonable doubt."

Hall was driving 83 mph, more than twice the legal limit of 40 mph, court documents show. He was also passing another vehicle in a two-way, left-turn lane and across double yellow lines, those documents say.

Police said Hall lost control of his 2004 silver Dodge Neon when he attempted to pull back into his lane.

"Hall's vehicle continued northbound out of control, subsequently colliding with two bicyclists traveling northbound in the east bike lane of Foothill Road," according to a probable cause declaration filed with the court. "As a result of the collision with the two bicyclists, one bicyclist was severely injured and the other bicyclist was fatally injured."

Before the murder charge was added, Cintean said Hall could have faced anything from five years probation to nearly nine years in prison.

The Hersevoort family has hired A. Peter Rausch to represent them in a civil suit, which has not been filed. Cintean said it's likely that the suit won't be filed until after the criminal case is decided.

"In my experience, most of the time the civil lawsuit is going to be filed after the resolution of the criminal case," he said. "It's much easier to proceed on a civil suit once a person has been convicted.

He said Rausch is likely to monitor the status of the criminal case to avoid any possibility of going beyond the statute of limitations.

Hall's next appearance, which will include a review of his no-bond status, is set for Monday.

Hall's father, Aaron, was arrested after police served a search warrant looking for evidence in their investigation into the accident that killed Hersevoort. Late last month, Aaron Hall pleaded not guilty to felony weapons charges after police said they discovered two illegal assault rifles and "thousands of rounds of ammunition" in a gun safe at the Halls' home in the 4200 block of Echo Court.

The elder Hall was charged with possession of a firearm by a convicted felon, possession of an assault weapon, possession of ammunition by a felon, and possession of a non-narcotic controlled substance. Police said the safe also contained four Daytrana patches, a stimulant used to treat ADHD, that Aaron Hall had without a prescription.

Court records show Aaron Hall has two felony convictions from 1994, for assault with a deadly weapon and firing at an inhabited dwelling. A pretrial hearing on the new charges is set for Aug. 28.