Norman Horwitz, a Washington neurosurgeon who helped successfully treat a D.C. police officer wounded by President Ronald Reagan’s would-be assassin in 1981, died Oct. 2 at his home in Chevy Chase. He was 87.

He died of complications from Parkinson’s disease, said his son Tony Horwitz, the author and Pulitzer Prize-winning journalist.

Dr. Horwitz was a professor emeritus of neurological surgery at George Washington University Medical Center, where his father had once served on the surgical staff. In a career spanning five decades, Dr. Horwitz trained generations of neurosurgical residents through his affiliations with GWU and MedStar Washington Hospital Center.

He drew the most public recognition as part of a team that removed an explosive bullet from the neck of Officer Thomas Delahanty, who was shot while escorting Reagan from the Washington Hilton Hotel on March 30, 1981.

Reagan was leaving the hotel after a speaking engagement when John W. Hinckley Jr. fired at him six times with a revolver. One of the bullets ricocheted off the door of Reagan’s limousine, piercing the president’s lung.

No one died in the assassination attempt, although press secretary James Brady took a bullet to the brain. Both Delahanty and Secret Service agent Timothy McCarthy were shot while trying to protect Reagan.

Dr. Horwitz assisted Michael Dennis in operating on Delahanty at the Washington Hospital Center. The doctors volunteered for the task despite being warned that the bullet could injure them if it detonated.

Dennis, who served under Dr. Horwitz as a resident and then became his medical partner for 20 years, said Dr. Horwitz was “instrumental in developing neurosurgery in the Washington area.”

Norman Harold Horwitz was born May 4, 1925, in Rochester, Minn., where his father, Alec Horwitz, was then a resident at the Mayo Clinic. His mother, the former Jean Himmelfarb, became a Washington lawyer.

Dr. Horwitz graduated in 1942 from Woodrow Wilson High School in the District. He completed his undergraduate degree at Princeton in two years and was a 1948 graduate of Columbia University medical school.

He was a post-graduate research fellow in neurophysiology at Yale University and a surgical intern at Massachusetts Memorial Hospital before serving in the Air Force during the Korean War. He was in the neurosurgical unit at Lackland Air Force Base in San Antonio.

After his discharge, he completed his neurosurgical residency at Yale and entered private practice in Washington in 1956.

He also joined the George Washington University medical school faculty and became an attending neurosurgeon at the university hospital before retiring in 1995. That year, he also retired as chairman of neurosurgery at MedStar Washington Hospital Center, a position he had held since 1987.

In the 1960s, Dr. Horwitz took his surgical teaching overseas to Afghanistan, India and Iran. He returned to Shiraz, Iran, in 1977 as a visiting professor of neurosurgery at Pahlavi Medical School. He also was a neurosurgical consultant at the MedStar National Rehabilitation Hospital in Washington and remained an active investigator at the Armed Forces Institute of Pathology at Walter Reed Army Medical Center, now known as the Walter Reed National Military Medical Center, after retiring from surgical practice.

Survivors include his wife of 62 years, Elinor Lander Horwitz of Chevy Chase; three children, Erica Horwitz of Scarsdale, N.Y., Joshua Horwitz of Washington and Tony Horwitz of West Tisbury, Mass.; a sister, Annetta Kushner of Annapolis; and seven grandchildren.

With Washington neurosurgeon Hugo V. Rizzoli, Dr. Horwitz wrote the influential medical book “Postoperative Complications in Neurosurgical Practice: Recognition, Prevention and Management,” which was first published in 1967. Dr. Horwitz also was a prolific contributor to medical journals and dispensed occasional medical opinions in the popular press.

In 1989 — on the bicentennial of the French revolution — The Washington Post asked Dr. Horwitz whether King Louis XVI of France could have remained conscious after being guillotined. Some experts speculated that the deposed king could have heard the crowd roar in delight as the blade cut through the monarch’s neck.

“I don’t think [any of this] is impossible,” Dr. Horwitz said.