A federal jury yesterday convicted a 28-year-old Washington man on four counts of using false written statements to purchase firearms from an Alexandria gun shop in 1979.

The panel deliberated for more than six hours in U.S. District Court in Alexandria Monday and yesterday before convicting Jimmy F. McEachern. An essential element of the case was whether McEachern's use of a Virginia driver's license as indentification when making a firearms purchase when he was not a Virginia resident was intended or likely to deceive the gun dealer.

Virginia law requires a person to be a current resident of the state in order to buy guns there.

McEachern purchased three rifles and two handguns from the Potomac Arms Corp. in Alexandria in 1979.

No sentencing date was set by Judge Albert V. Bryan Jr.

McEachern, a Muslim who uses the name Yusuf Abdul Haseeb, could be sentenced to as much as 20 years in prison and fined $20,000. The judge set bail at $25,000. McEachern had been free on personal recognizance since his arrest in January.

The defense argued that McEachern had no prior criminal record and purchased the weapons for protection of a Muslim group. The defense also stressed testimony that indicated McEachern told clerks at the gun store he was a Virginia resident when he purchased a rifle in the first of four trips there.

Four Potomac Arms clerks testified that if a prospective gun purchaser said he did not live in Virginia, they could not sell to him.

Defense attorney Joe Dyer produced evidence that the guns had never been used for criminal acts.

Assistant U.S. Attorney Nash W. Schott argued that McEachern bought the guns in Virginia because of stricter gun laws in Maryland and the District of Columbia.