The old granite courthouse in Ellicott City will become a bastion of intense security and a focus of media attention for two months beginning today as Eric Tirado stands trial in last March's slaying of State Police Cpl. Theodore D. Wolf.

Not since the 1970s, when H. Rap Brown was tried there on charges of inciting a riot in Cambridge, has there been as much police protection in evidence at the 19th-century courthouse that sits on a a knoll old-timers call Mount Misery.

State police investigating the murder interviewed more than 250people in Maryland, New York and Virginia before charging Tirado, 26, and Francisco Rodriguez, 21, both of the Bronx, N.Y., with fatally shooting the trooper March 29, 1990, during an early-morning traffic stop on Interstate 95 in Jessup.

Rodriguez, who was recently convicted in a drug conspiracy case in federal court in Virginia, will be tried later. Prosecutors are seeking the death penalty for Tirado, who they allege was the trigger man.

Jury selection is expected to take two weeks, with the largest jury panel in county history being called. Prosecutors and defense lawyers will interview some 500 prospective jurors to determine how they feel about the death penalty and whether publicity about the case has affected their judgment.

On a more mundane level, the jurors will be asked to commit themselves to the case for as long as 10 weeks, at a time when many are thinking about their summer vacation or reclining on the beach in Ocean City.

"It could be the longest trial in the recent history of the county," said Timothy Wolf, an assistant county state's attorney who is one of two prosecutors arguing the state's case against Tirado before Circuit Court Judge Raymond J. Kane Jr.

The state contends that Tirado shot Corporal Wolf as he was seated in his patrol car after making a traffic stop. Police have said in court documents that Tirado's fingerprints were found in a Chevrolet Nova stolen in Alexandria, Va., that is believed to be the car Corporal Wolf had stopped.

"The case obviously is of great concern, not only to this office but to all police officers and citizens, because a law enforcement officer was killed in the line of duty," said Michael D. Rexroad, chief of the state's attorney's Circuit Court division and Mr. Wolf's co-counsel.

Representing Tirado are former prosecutor Mark Van Bavel, a Baltimore lawyer, and William Kanwisher, an assistant public defender. Mr. Van Bavel said he has tried two capital cases as a defense attorney, both involving prisoners charged with murder.

One case ended in acquittal, and in the other there was a hung jury before the defendant pleaded guilty and was sentenced to a life term to run concurrent with one he was already serving.

"We think we can get a fair trial from the people in Howard County and the trial judge," said Mr. Van Bavel, who said he did not seek to move the trial because "the publicity about the case has been statewide and even national."

The defense attorney, who has shown a bulldog resolve to learn more about the state's case during pre-trial motions, said that "right now, it looks strictly like a circumstantial case."

He said Tirado, who once had ambitions to be a transit officer in New York City but did not complete the training, was aware that he is "on trial for his life" despite his lack of emotion in the courtroom. "It will be a long and tough case," the defense attorney said.

The county's state's attorney, William R. Hymes, is bemoaning the impact of the trial on his office's tight budget, saying it could cost $60,000 or more to house, feed and transport the large number of state's witnesses.

In terms of security, the courthouse appears ready for anything. Plainclothes state troopers, supplemented by deputy county sheriffs, have been in evidence throughout the courtroom and are patrolling the parking lot during the motions hearings.

When Tirado is taken in a deputy's car back to the county detention center in Jessup, there is a state police cruiser in front and behind.

During hearings, the late trooper's widow, Ginny Wolf, takes notes from the second row behind the prosecutor's trial table, while Tirado's father and family members sit in the second row behind the defense lawyers. Except for a few joking exchanges with his family during breaks in the hearings on motions, Tirado is stone-faced in the gray suit he invariably wears to court.

The heavy shadow of a beard that Tirado sported when he was arrested is now shaved, although he still has a mustache. The prosecution failed in its bid to get Judge Kane to order Tirado to grow back his beard so he would look the same as he did 15 months ago when Corporal Wolf was shot.

Even though Tirado faces the death penalty if convicted, there is little precedent in Howard County for such a sentence. And in the state of Maryland, no one has died in the gas chamber since June 9, 1961, when Nathaniel Lipscomb was executed for murder and rape.

During the 13 years of his tenure as state's attorney, Mr. Hymes' office has asked for the death penalty four times after a conviction but has never gotten it. "I don't feel there is any predisposition against the death penalty here," he said. "It just didn't happen in those cases."

"In one of those capital cases, the mother of a 22-year-old defendantcame in to say her son was a victim of drug abuse and pleaded: 'Don't kill my son,' and it had an effect on the jury," Mr. Hymes recalled.

Retired Circuit Judge James Macgill, who presided from 1955 to 1980, said he ordered the death penalty for an inmate who killed a fellow prisoner during the 1960s. The sentence, however, was subject to a lengthy appellate review and was eventually commuted to life imprisonment.

"My guess is that not since the end of World War II has there been anyone put to death in Howard County," Judge Macgill said.

Richard J. Kinlein, a former county state's attorney, said he believed that the last time the death penalty was imposed in the county was a hanging at the turn of this century. He said his uncle, the late Charles Hogg, who practiced law in Ellicott City, told him they built the scaffold on Emory Street near the old jail behind the courthouse.

The day after the hanging, he recalled his uncle's telling him, the carpenter who built the scaffold committed suicide, leaving some of the townsfolk with a feeling of consternation.