After a frantic firefight with police that ended with the death of his brother, terror suspect Dzhokhar Tsarnaev spent his last hours of freedom hiding just two-tenths of a mile from where he ditched his stolen getaway car.
While experts give high praise to law enforcement for the manhunt, the decision to set up a perimeter that just missed Tsarnaev's ultimate hiding spot is almost certain to be scrutinized for what went right, and what went wrong.
The terrible night began right outside Peter Kahayias' Laurel Street home when he was awakened by a ferocious firefight. More than 200 rounds were fired between the police and the Tsarnaevs, who also threw a pressure cooker bomb and several pipe bombs.
"I said Jesus, little sleepy Watertown. Why (did) they come here?" Kahayias said.
When the younger Tsarnaev drove off, running over his brother on the way, he made it just a half-mile down Spruce Street, stopping at the corner of Lincoln and Spruce. Then he took off on foot.
The army of law enforcement was on its way, but in the meantime the initial force of officers had to deal with a dead or dying terrorism suspect and one of their own in serious trouble: MBTA police officer Richard Donohue shot in the groin and bleeding out through a pierced femoral artery – possibly shot by friendly fire.
A decision was made to set up an approximately 20-block perimeter where police believed Tsarnaev would be. It was a crucial decision that would have broad implications for how the rest of the day played out.
As the world now knows, Tsarnaev was hiding inside a boat parked at Franklin Street, a little more than two-tenths of a mile away from where he ditched the SUV he had driven away in.
Watertown police Chief Edward Deveau explained what happened.
"We know he didn't go straight to the boat. When we set up the perimeter with the best intentions with a lot of information. We found blood in the car that he abandoned, they found blood behind a house inside the perimeter, so we had no information that he had gotten outside our perimeter," Deveau told the media shortly after he was captured.
"As we said, it was very chaotic. Early this morning, we had to aid a police officer that was shot, bleeding, so there's a lot of things going on. We thought we had the perimeter solid and we pretty much did that but we were about one block away," he said.
When deciding where to set perimeters, law enforcement typically takes into account suspects' last known sightings, wounds, if any, and which way they ran, according to retired FBI agent Jeffrey Horblit, who is now president of Northeast Intelligence Group.
"Was that a miscalculation not to include that street in the perimeter?" FOX Undercover reporter Mike Beaudet asked Horblit.
"No," Horblit replied. "I don't think so. I think when you look at where the original shootout took place and where he's ultimately apprehended, there's literally hundreds of homes."
Former Navy SEAL Jonathan Gilliam, who went on to work for the FBI after leaving the Navy, said the military sets up perimeters for searches probably every day in Afghanistan. Gilliam, who retired from the FBI this past November and is now president of United States Continued Service, also defended the perimeter in Watertown, saying sometimes even the SEALs' perimeters miss their men.
"They probably tried to concentrate the area they thought the individual had fled to and they probably cordoned that off as good as they could and it's common for the individual you're searching for even in a war zone to not be in the grid area," he said.
Boston and Watertown police declined to comment for this story, citing the ongoing investigation.
Back in Watertown, dawn brought a new mission for the hundreds if not thousands of police and federal agents: painstaking house-to-house searching led by tactical teams. Authorities ordered the region to shelter-in-place.
On Laurel Street, from where Tsarnaev fled, Kehayias was puzzled when the searching began there around 7 a.m.
"They're looking down here when they got one dead right in the corner and the other one went that way," he said.
The hours dragged on with many false starts, but no suspect. As the day began to wane, Gov. Deval Patrick announced the lifting of the shelter-in-place order and State Police Col. Timothy Alben announced his force was pulling back.
"We are going to draw back our tactical teams but the State Police will be providing additional patrols to the town of Watertown over the next two to three days," he told the media. "Our presence here today is about the safety of the people in the community. We're confident we did that to the best of our ability unfortunately we don't have a positive result."
Gilliam, the former Navy SEAL, gives the police on the ground high praise, but says politicians botched the call to lift the shelter-in-place.
"I absolutely think that was the wrong decision," he said. "The public safety comes first and unfortunately what makes the public safe sometimes is not what makes them comfortable."
In a strange twist, it turned out to be the lifting of that order that led to Tsarnaev's capture. A homeowner on Franklin Street stepped outside for some fresh air and to check out his boat. His discovery of Tsarnaev inside the vessel then led to his capture.
FOX Undercover's Beaudet asked retired SEAL Gilliam, "Should they have been able to catch him sooner?"
"That's where you're getting down to Monday morning quarterbacking. It's hard to tell. We don't know exactly what was going on in the ground. I can tell you from my point of view what allows these law enforcement agencies to work together better, which is more training together, putting egos aside," he said.
"Do you think we're lucky things ended as well as they did?" Beaudet asked Gilliam.
"Absolutely," he replied.
Retired FBI agent Horblit didn't think it was luck, though.
"I don't know if I would call it luck. In many cases, you make your luck and I think the hard work helps you create your luck, and I think the hard work here is putting the pressure on," he said.