THE DISTRICT

Mother sentenced: A District woman who killed her infant child by giving her an overdose of methadone was sentenced yesterday to 10 years in prison by a D.C. Superior Court judge.

Tracey Cobb, 38, of the 1600 block of Sixth Street NW, was sentenced by Judge Ann O'Regan Keary after her guilty plea to charges of voluntary manslaughter and cruelty to children.

Prosecutors described Cobb as a longtime heroin addict, and she had access to methadone through her participation in a drug treatment program.

She routinely gave doses of the narcotic to her sickly 10-month-old infant because she thought it made the child feel better, she told authorities. On Jan. 31, Cobb gave her daughter a dose so large that it killed her.

Bank robbery: A robber passed a note demanding cash and fled with about $9,500 from a downtown bank after failing a few minutes earlier at another bank.

The man -- in a white T-shirt, jean shorts and sports goggles -- tried to rob the Adams National Bank in the 1500 block of K Street NW about 10:40 a.m. but got nothing and left, police said. But he got a bag of cash at a Riggs Bank in the 1100 block of 15th Street, police said.

Police asked anyone with information to call 202-727-9099.

Arson sentence: A 58-year-old District man who tried to burn down his apartment building was sentenced yesterday to six years in prison by a D.C. Superior Court judge.

Paul M. Dubois, of the 1000 block of Sixth Street SW, was sentenced by Judge Wendell Gardner after a jury convicted him of arson, destruction of property, second-degree burglary and obstruction of justice.

DuBois was convicted of splashing gasoline on the carpet in front of his apartment in the Marina View Towers on July 23, 2003, and then igniting it.

He was the only person injured in the blaze. He was later found lying in the apartment's courtyard, clad only in his underwear.

VIRGINIA

Possible gang incidents: Fairfax County police said yesterday that two apparently gang-related episodes had occurred about a week apart on the same block of Monticello Drive in the Falls Church area but that the incidents were not linked. Two suspects were identified in one of the cases.

The first incident occurred about 2 a.m. July 30, in the 2900 block of Monticello Drive, when six people assaulted and robbed a 34-year-old man who was walking home, then beat and robbed a 32-year-old bicyclist who was passing by.

A 26-year-old woman, Jeannette Benitez, who lives on the block, was arrested later that day. Yesterday, police said they were searching for a second suspect, Jaime Ramos, 28, and said he was a known member of the gang Mara Salvatrucha.

On Thursday night, police said four teenagers were walking in the same block of Monticello Drive about 10:30 p.m. when a car pulled up and four shots were fired at them. A 15-year-old boy was wounded in the leg. Police said they believed the assailants were gang members but said the victim and his friends were not gang members.

Sentence in killing: An Arlington man who shot and killed his ex-girlfriend in Annandale last fall was sentenced by a Fairfax County Circuit Court judge yesterday to serve 38 years in prison.

A Fairfax jury convicted Arnoldo Aleman, 42, of second-degree murder in April. A witness said she watched Aleman shoot Maria Mercedes Morales-Vanegas, 40, in the chest when she arrived Sept. 8 at her townhouse in the 7800 block of Patriot Drive. "It's justice for Maria," Fairfax Assistant Commonwealth's Attorney Dennis M. Fitzpatrick said. "The jury stood up for Maria."

Compiled from reports by staff writers.