Jeffrey Leon Beard, a 23-year-old former tour bus driver, was sentenced yesterday to a minimum prison term of 15 years and four months for his part in an attempted armed robbery at a Northwest Washington laundromat and for threatening his accomplice in an attempt to keep him from testifying in the case.

Beard was convicted on Oct. 18 in D.C. Superior Court of assault with intent to commit robbery while armed, carrying a pistol without a license, threatening to injure a witness and obstruction of justice. He was sentenced to a maximum of 47 years on the four counts.

He was found not guilty of charges that he tried to have the accomplice murdered to silence him. Those charges stemmed from a complicated police hoax in which the accomplice, Darryl Smith, cooperated with police in making photographs depicting him shot to death.

Smith was arrested for the 1983 attempted robbery of the laundromat at 1820 First St. NW. He pleaded guilty, told police that Beard had put him up to it, and became a witness for the prosecution against Beard.

After police received a tip that Beard allegedly was looking for someone to kill Smith for pay, an undercover officer posed as a hired killer and met with Beard to make arrangements. Police videotaped the undercover officer handing Beard the faked photographs of the "dead" Smith and arrested him for solicitation of felony murder.

Beard testified that he never intended to kill Smith but that he was trapped by police into going along with the scheme and was too scared to back out.