The patient records of Fairfax County psychiatrist Paul J. Peckar have been reviewed but no conclusive evidence has identified who mailed a pipe bomb that severely injured Peckar this month, according to federal investigators.

"There's not a lot to tell. We have a big net out there and we're following the leads," said Paul Giroux, a spokesman for the Postal Inspection Service, which is leading an investigative team of local and federal agents.

Peckar, 50, was burned over 55 percent of his body June 1 when he opened a mail bomb delivered to his third-floor office in the Sherwood Hall Medical Center in Mount Vernon.

Peckar remains in critical condition at the Washington Hospital Center.

"We expected him to be critical for quite a while because of the burns and possibility of infection," hospital spokeswoman Carol Baney said.

Fairfax County Supervisor Gerald Hyland, a family friend of the Peckars, said the doctor suffered a high fever over the weekend and has had at least three skin-transplant operations.

Hyland said Peckar's family has "held up remarkably well under the circumstances."

Pam Peckar, the doctor's wife, has visited her husband daily since the incident, he said.

"Dr. Peckar recognizes her, but in terms of knowing what has happened to him, the focus has not come together," said Hyland, adding that investigators have not been able to question Peckar.

Hyland said the community has shown strong support for the Peckars through donations to the Paul J. Peckar Fund, which can be contacted at 2516 Sherwood Hall Lane, Suite 305, Alexandria, Va., 22306.

The Postal Service is offering up to $50,000 for information leading to an arrest and conviction in the case. The service can be reached at 636-2382.