A Washington man shot in the back by a District police officer during a narcotics arrest more than two years ago was awarded $303,000 in damages yesterday by a D. C. Superior Court jury.

The victim, Stanely Lawrence, 36, is paralyzed from the chest down as a result of the injury and now resides at the Glenn Dale Hospital in Maryland. He sued the District government, contending that police used excessive force in carrying out the arrest, according to his attorney, Roger C. Spaeder.

The jury of seven women and five men deliberated 90 minutes before making the award after a six-day trial before Judge Frederick Weisberg.

In announcing the verdict, the jury foreman said that $203,000 was awarded for Lawrence's lost wages and for past and future medical bills incurred as a result of the injury and subsequent rehabilitative treatment, Spaeder said.

The additional $100,000 was awarded to compensate Lawrence for pain and suffering, Spaeder said.

Assistant D.C. Corporation Counsel Michael S. Levy, who represented the District government, argued that the police officer had fired in self defense after Lawrence displayed a weapon. The incident occured on July 20, 1976, at 14th and T streets NW.

According to Spaeder, Lawrence has served three years in prison after five convictions related to drug offenses and one conviction of larceny after trust. Lawrence, who is confined to a wheelchair, testified at that he was a heroin addict at one time and sold drugs to support his habit, Spaeder said.

Two District police officers confronted Lawrence on the night of the incident based on a tip from an informant that Lawrence was selling narcotics. Officer Anthony J. Zgainer, who now works for a Pennsylvania police force, approached Lawrence with his gun drawn and forced him up against a nearby automobile. Spaeder contended. He then was joined by Officer Vance Beard, who still is a member of the District police department Spaeder said.

Lawrence acknowledged that he was armed that evening, but four eye-witnesses supported his testimony that he dit not draw his weapon during the incident, Spaeder said.

Following the incident, Lawrence was charged with possession of seven packets of heroin, assaulting a police officer and a gun violation, Spaeder said. A federal judge later dismissed the case because, the judge said, the informant's information did not give the officers probable cause to arrest Lawrence, Spaeder said.