A Maryland State Police emergency medical helicopter crashed in a Baltimore city park early yesterday, killing the pilot and an aviation trauma technician, both of whom were state troopers. The two were returning to their base in Frederick after delivering a shooting victim to the University of Maryland Hospital.

Cpl. Gregory Alan May, 31, of Hagerstown, a nine-year police veteran, and the trauma technician, Trooper 1st Class Carey Suzanne Poetzman, 28, of Manchester, a six-year veteran of the force, died in the crash.

Poetzman is the first woman Maryland state trooper killed in the line of duty, according to police spokesman Sgt. Bill Tower.

The cause of yesterday's crash of the Bell Jet Ranger was not immediately known.

Tower said the wreckage was found in a heavily wooded area on the fringe of Leakin Park, about 250 yards off Hilton Parkway in west Baltimore and less than three miles from the hospital's Shock Trauma Unit, where the troopers had transported Michael David Finecey, 20, of Sykesville.

Finecey accidentally shot himself in the head while cleaning his father's .32 caliber revolver at about 3 a.m. yesterday in his father's home in Eldersburg, police said.

Finecey was reported to be in good condition yesterday by hospital officials.

The police helicopter lifted off from the hospital helipad in downtown Baltimore at about 4 a.m. to return to Frederick, according to Tower.

But when the daytime crew reported for duty at Frederick at 6:30 a.m., they found the hangar empty, Tower said.

A search was started for the missing helicopter in the area around Ellicott City and Patapsco State Park in Howard County, because radar reports from Baltimore-Washington International Airport indicated that the airport had lost radio and radar contact with the helicopter when it was about 12 miles northwest of the airport.

At 1:47 p.m., Baltimore City police reported that they had found the wreckage in Leakin Park, which appeared to be along the path that the helicopter would have taken to return to Frederick, Tower said. He said the helicopter had crashed about eight miles from the area being searched.

The deaths bring to six the number of Maryland state troopers who have died while flying in police helicopters, Tower said.

Two troopers were killed on a medical evacuation mission on Oct. 28, 1972, in Grasonville, Queen Anne's County, when their helicopter crashed in heavy fog, and two were killed while on a traffic patrol assignment Sept. 18, 1973, in Beltsville when their helicopter experienced mechanical problems and crashed.

Tower said the medical evacuation program, which began in 1970, has flown more than 20,000 missions.

State police have 31 pilots who fly 10 helicopters for the evacuations and aerial surveillance, he said.