With the immediate elation evaporating, some investigative experts are looking harder at how long it took to capture two men accused in the Washington, D.C.-area sniper shootings. And they are concluding that maybe it took too long.

They say that missed chances to catch the pair reflect underlying weaknesses in policing big crimes.

These authorities call for better and more widely shared computer tools to track crimes, fingerprints and guns, more and better-trained police, and stronger coordination in immense and complex investigations.

Some experts caution against the wisdom of hindsight.

"I think you would find some mistakes in almost every serial murder investigation," says Steven Egger, a former Michigan homicide investigator who wrote "Killers Among Us: An Examination of Serial Murder and its Investigation."

The case was solved, authorities say, only when a man -- apparently the sniper -- called and suggested that investigators check connections with a murder-robbery in Montgomery, Ala. A fingerprint in that case matched one in a national database, providing the name of John Malvo and a trail to his alleged partner in the serial shootings, John Muhammad.

"This wasn't some supersleuthing," says John Baeza, a retired New York City police detective who consults on crime for companies. "This was just somebody calling in and the police doing their job."

Still, investigators passed by an extraordinary number of promising paths, starting more than 18 months ago. Some might have led to quicker arrests; some might have set the two men on another course, toward a less horrific future. No one will ever know.

At least three times, for example, people in northwestern Washington state complained about Muhammad and Malvo to federal authorities in the months after the terrorist attacks of Sept. 11, 2001. They said the pair talked of carrying out a sniper attack. Local police say there was no evidence of a crime, and there is no sign that authorities ever interviewed either man.

"We tried hard to get some attention from authorities," lamented the Rev. Alan Archer, director of a homeless shelter who tried to alert federal investigators.

Should authorities have done more?

"In today's world post 9-11, I probably would have said, 'Geez, it's probably worth sending somebody out,'" said Gary Penrith, a retired FBI agent who investigated extremist groups and later oversaw foreign counterintelligence at bureau headquarters.

However, Sue Aguilar, CEO of WeTip, which contracts to handle anonymous tips for police departments, says public tips are sometimes overlooked because "law enforcement is so overworked." More staff and money are needed, she said.

In Alabama, before the killings around the nation's capital began, local police found a fingerprint at a robbery-murder scene that would later turn out to be an important clue in the sniper investigation. It matched a print that was on file with federal authorities. But no one checked the federal database until the tipster called, revealing the Alabama connection.

Police first checked a state database of fingerprints. That is standard procedure, but it took weeks -- during which the sniper killings occurred.

"There's no reason they couldn't have checked both at the same time," suggested Egger, the former homicide investigator.

But others say limited money and manpower prevent the use of the broadest, fastest checks in many cases. With the normal backlog, it can take months to match a print in a routine case. The new focus on fighting terrorism has added to pressures on the system, law enforcement officials say.

During the sniper shootings, Muhammad's car was stopped by police at least once and, according to some news reports, at least twice more. But authorities and citizenry were focused on finding a white van or truck mentioned by witnesses. Those witnesses turned out to be wrong.

Some of the early missed signals stem from the reluctance of investigators to follow up aggressively on mere warnings or threats, said Richard Walter, a consultant who helps police agencies evaluate patterns within crime cases. He blames overly restrictive investigative rules, a legacy of rights abuses dating to J. Edgar Hoover's days as FBI director.

Those rules, designed to protect the free-speech and privacy rights of suspects, bar a full investigation without a "reasonable indication" threats will be carried out.