U.S. Park Police officer William J. Grissam died suddenly while on a routine bicycle patrol in the District 72 years ago. Although his death made brief headlines, Grissam's legacy was largely forgotten until several Park Police officers stumbled across his story while researching their department's history.

In May, seven decades after the 54-year-old died in an apparent bicycle accident, Grissam's name was added to the National Law Enforcement Officers Memorial at Judiciary Square downtown.

Last month, after investigators tracked down his daughters in Maryland, the department held a brief ceremony commemorating Grissam's service.

"No police officer should ever be forgotten when they die in the line of duty," said Detective Jonathan Crichfield, who was part of the research team. "This was important to do."

Several years ago, Crichfield, Lt. G. William Davis, Maj. Henry Berberich and several other current and retired police officials started working on a history book about the force.

The officers had heard that one of their own might have died in the line of duty in the 1930s, but they weren't sure. About three years ago, Davis said he began going through old clippings on microfilm at the Martin Luther King Jr. Library when he found stories about Grissam's death.

The articles were enough to get Grissam's name added to the National Law Enforcement Officers Memorial.

"It was sort of, 'Bingo, there it is,' " Davis said. "I felt good about finally finding something that we could use to recall our own."

Park Police commanders said the investigators' work helped bridge a gap in their history.

"When someone gives their life to their country and community, it's the least we can do to honor them," said Park Police Capt. Kevin C. Hay. "If we forgot to put someone's name on the memorial, it's incredibly important that we rectify that wrong."

Although authorities have now memorialized Grissam's death, the circumstances surrounding his accident are still mysterious, according to stories unearthed by the Park Police history detectives.

The officer was riding his bicycle near Judiciary Square when he met a colleague about 5 a.m. on March 20, 1932, and said he was going to pedal up to the Smithsonian to conduct another patrol.

About 15 minutes later, according to newspaper accounts, a taxi driver found Grissam lying unconscious on the pavement. His bicycle was propped against a parked car. He died hours later at old Emergency Hospital. He had suffered a cracked skull and broken ribs, according to press reports.

Because they had no witnesses, police at first speculated that Grissam might have been killed by a hit-and-run driver, according to newspaper accounts. Later, after a coroner's inquest, detectives determined that Grissam had crashed his bicycle into a parked car. The death certificate shows that someone crossed out the original ruling -- "Hit and Run Accident" -- and wrote down "Run into auto while riding bicycle," according to Park Police.

Grissam -- a veteran of the Spanish-American War, the Philippine Insurrection and World War I -- is among 10 Park Police officers to die in the line of duty, officials said.

Park Police believe there might be one or two others who have not been included in that tally.

However, even after Grissam's name was added to the memorial, investigators said they did not feel their work was complete.

They wanted to locate the officer's relatives and pass along an American flag that had flown over the U.S. Capitol. Family members of law enforcement officers who die on duty are given those U.S. flags during a ceremony at the national memorial in May.

Crichfield, the Park Police detective, began digging through census reports from 1930 in search of Grissam's family members. After combing through the records, Crichfield came across Grissam's listing, which showed he had a wife and two daughters, Helen and Marjorie.

With the help of computer databases, Crichfield discovered the daughters were still alive -- and living in Hyattsville.

One of the daughters, Marjorie Rose, answered the phone when Crichfield called last month to tell her that her father's name had been inscribed on the memorial. The other daughter, Helen Grissam, is 94 and living in a nursing home.

Rose, 86, said in an interview that she vividly recalls the day a Park Police officer brought her different news -- about her father's accident.

An officer knocked on her front door, Rose said, and told her mother that she needed to get to the hospital quickly because Grissam had been hurt badly.

By the time the family reached the hospital, her father had died, said Rose, who was 14 at the time.

Last month, Park Police took Rose, her son and daughter-in-law to check out Grissam's name on the wall. Police then drove the family in a motorcade to the department's Anacostia station house to present Rose with the U.S. flag and other mementos.

"It was just wonderful," Rose said. "Anybody on the Park Police force today wouldn't know [Grissam], nobody knows him. With all these years in between, I'm glad it came to closure."

News researcher Bobbye Pratt contributed to this report.

U.S. Park Police Detective Jonathan Crichfield, left, and Lt. G. William Davis got officer William J. Grissam's name added to the National Law Enforcement Memorial 72 years after Grissam's death.