The prosecution team in the Hinckley case includes two longtime veterans of the U.S. attorney's office and a lawyer who left a prestigious uptown Washington firm to work for the government.

Roger M. Adelman, 41, the chief prosecutor in the case, joined the U.S. attorney's office here 12 years ago, after two years in the U.S. Army as a Russian linguist and a year in private law practice in Philadelphia.

A colleague decribed Adelman--a lanky bachelor and baseball fan who favors bright-colored ties--as the "single most experienced trial lawyer" in the prosecutor's office, an intense worker known for his long hours on the job. He is also a veteran student of the insanity defense, which will be the focus of Hinckley's trial.

Adelman, a graduate of Dartmouth College and the University of Pennsylvania Law School, last year succesfully prosecuted former representative Richard Kelly, a Florida Republican, on Abscam bribery charges.

Assistant U.S. Attorney Robert R. (Dick) Chapman, 39, who has worked closely with Adelman and will help him try the Hinckley case, has spent 11 years in the prosecutor's office.

Chapman, like Adelman, is assigned to the major crimes division, an elite group of veteran prosecutors who handle the most serious, violent criminal cases to come through the office--from international weapons sales to narcotics conspiracies. Chapman--whose desk is usually covered with an extraordinary assortment of pipes and tobacco--is a graduate of the University of Iowa Law School and was a lieutenant in the U.S. Navy Judge Advocate General's Corps before he came to the U.S. attorney's office.

The youngest member of the prosecution team is Marc B. Tucker, 32, who left private law practice with Washington's Covington & Burling to come to the U.S. attorney's office in 1979.

While Adelman and Chapman have focused on preparation of the case for trial, Tucker--a graduate of Columbia Law School--has concentrated on the legal analysis needed for pretrial arguments.