A Washington man was sentenced in U.S. District Court yesterday to 10 to 45 years in prison for bank robbery and murder in connection with the death of an 85-year-old housekeeper who was fatally injured by a speeding getaway car last October.

Joseph T. Lockett, 33, was with two other men in a car that struck Helen Helbert Oct. 18 as she was crossing the street at Connecticut Avenue and Albemarle Street NW.

Helbert, a nurse and housekeeper who had lived with a family on Albemarle Street for more than 30 years, died the following day.

The prosecutor's office and police investigators said that Lockett and the two other men were fleeing from an aborted robbery at the Tenley Circle branch of the American Security Bank at 4445 Wisconsin Ave. N.W.

Joseph Harold H. Greene sentenced Lockett to serve seven to 30 years for killing a person in an attempt to escape from a bank robbery. Lockett also had pleaded guilty to a separate robbery at the Riggs Bank branch at 1875 Connecticut Ave. NW. Greene sentenced him to three to 15 years on that charge, and ordered the sentences to run consecutively.

Greene also sentenced Preston K. Procter Jr., 43, to three to nine years in the Oct. 15 robbery at Riggs. Proctor was the owner of the car that struck Halbert and was a passenger in the car at the time, the court was told. Charges against Proctor in the woman's death were dismissed after his guilty plea to the robbery.

A third man, Lucius F. McKoy, 46, who was said to be driving the vehicle when it struck Helbert, is scheduled to be sentenced by Greene on May 23. McKoy has pleaded guilty to the Oct. 18 bank robbery and to a charge growing out of Helbert's death.