A Montgomery County jury convicted a Maryland man yesterday of assaulting a woman and carjacking her Mercedes before leading police on a chase through five Maryland jurisdictions with the woman's two children in the back seat.

The jury failed to reach verdicts on two kidnapping charges against Carl E. Jones. Circuit Court Judge Louise G. Scrivener declared a mistrial on those counts. She set an Oct. 12 sentencing date for the carjacking and assault charges.

"We're pleased with the verdict," said Rene Sandler, Jones's attorney. "We respect the jury's verdict, and we respect the rulings of the court."

Montgomery County State's Attorney Douglas F. Gansler said he will not decide whether to put Jones on trial again on the kidnapping charges until after he is sentenced for carjacking and assault.

"We can't make an informed decision until we see what the sentence is," Gansler said. Jones "is facing 40 years in jail. . . . He'll be locked up in a cage and won't be in a position to hurt another family."

Jones could receive up to 30 years for carjacking and 10 years for second-degree assault.

Each kidnapping charge carried a possible sentence of 30 years, so if Jones had been convicted on all four counts against him, he could have been sentenced to as much as 100 years in prison.

It became apparent soon after jurors began deliberating Thursday that they disagreed about the kidnapping charges. In several notes to the judge, they asked how Maryland law defines kidnapping.

They asked about whether Jones had to have touched the children to be convicted of kidnapping. "No," the judge replied. They asked whether Jones had to intend to take the children for the incident to have been kidnapping. "No," said the judge. They asked whether he had to have known they were in the car. Scrivener told them he did.

After more than eight hours of deliberations, the jury concluded it could not reach a verdict on the kidnapping charges.

Jones's attorneys had planned to argue in his defense that he was under the influence of drugs while driving the car. Scrivener excluded that defense before the trial, so the defense centered on the fact that Jones may have taken the Mercedes sport-utility vehicle but did not mean to kidnap the children.

The incident occurred July 15. In all, Jones allegedly led authorities on a two-hour chase through six jurisdictions, some repeatedly. Authorities said the pursuit began after they saw him driving a stolen Infiniti in Baltimore. A half-hour into the chase, police said, the Infiniti ran out of gas in Montgomery, and Jones carjacked the Mercedes.

Marna Plaia, 32, and her children -- Paul, 3, and Edie, 18 months -- were in the Mercedes heading home to Great Falls from a relative's house in Potomac when Jones stepped in front of Plaia's car, Plaia testified earlier this week.

He pulled Plaia from the car and threw her on the ground, she testified.

With the two children on board, Jones then allegedly drove the Mercedes at speeds of up to 130 miles an hour, police said, leading them from Montgomery, to the Capital Beltway, to Interstate 95, then north to Baltimore County. Then he drove south on I-95 to the Beltway, where he took Route 50 east toward Annapolis, police said.

Police finally stopped Jones in Anne Arundel County near the Prince George's County line, officers testified at trial. The children were unhurt.

Jurors declined to comment yesterday as they left the courtroom, so it was unclear how many did not believe Jones kidnapped the children.

Plaia sobbed lightly yesterday in court when the jury foreman announced that the jury was deadlocked on the kidnapping charges. She and her family, who sat through most of the three-day trial, declined to comment when they left the courtroom.

"We're not looking forward to putting her and her family through a trial again," Gansler said, referring to Plaia and her husband. And depending on the sentences Jones receives on the other charge, another kidnapping trial "may not be necessary," Gansler said.