As a huge manhunt continues for an Army reserves specialist who has been named the prime suspect in a mass shooting, there are several theories as to how he has managed to evade capture.
Police are on the hunt for Robert Card, 40, who killed 18 people and injured 13 more after he opened fire at two separate locations in Lewiston, Maine. He was sectioned several months ago due to mental health reasons, and before leaving the Army he claimed he was hearing voices and threatened to shoot up the National Guard base in Saco, Maine.
After revealing Card to be their suspect, police searched his home where they discovered a suicide note addressed to his son. Card had targeted a bowling alley hosting a children's league and a popular bar on Wednesday evening, walking in with an AR-15 rifle before opening fire.
READ MORE: Childhood best friends died trying to stop evil Maine gunman who is still on the run
Police were called at 6.56pm local time about a shooting at Just-In-Time Recreation, with police saying seven people were killed at the bowling alley. Just minutes later, at 7.08pm, several 911 calls came in reporting a gunman at the restaurant Schemengees Bar and Grille, around four miles from the bowling alley.
Brit 'saw her insides' after being cut open by propeller on luxury diving tripEight people died in the restaurant shooting with three more later dying in hospital. As the search for Card continues, shelter-in-place orders have been issued as far north as the US-Canada border with police warning that he is armed and dangerous.
But just how has Card evaded capture for almost two days? As more details are revealed about Card and his life, there are four main theories as to how he's escaped detection.
Mobile phone left to throw cops 'off his scent'
As FBI agents carried out a dramatic raid on a family property on Thursday night, they discovered a mobile phone thought to belong to Card. Multiple police vehicles were spotted outside his home in Bowdoin, Maine, as authorities said they were executing "several search warrants".
Loud bangs were heard at the scene with police yelling to Card over a megaphone to surrender. They were reportedly not sure whether Card was in the house, but a spokesperson for the Maine Department of Public Safety said officers were "simply doing their due diligence by tracking down every lead in an effort to locate and apprehend Card."
It's believed Card left behind his cellphone, which has been recovered by authorities, suspecting it could be tracked. Within several hours of arriving at Card's home, police left, though said they would be returning to retrieve evidence.
Card may have disguised himself and 'could be anywhere'
Law enforcement experts have warned that Card could have changed his appearance or be wearing a disguise in order to escape detection. Former Florida police sergeant and SWAT team member Marko Galbreath warned that Card could have travelled anywhere, and the entire country must be vigilant.
He said Card could still be in the area, hunkering down and planning to have a shoot-out with police if it comes to it, or he could be across the other side of the country by now. Mr Galbreath also said Card could have changed his appearance in order to escape detection.
"He could have shaved, he could have put on a wig, he may change his appearance," he warned. "He may not look like what people think he looks like, so we need to really watch."
Knowledge of the area and military training could help Card remain undetected
As authorities race to track down the gunman, his military training could play a key role in his evasion of detection. A former colleague said Card, who is thought to have joined the reserves in 2002, is a skilled marksman and outdoorsman.
They described him as one of the best shooters in his Army Reserve unit. He has also received a number of military awards including the Army Achievement Medal, Army Reserve Component Achievement Medal, Humanitarian Service Medal, National Defense Service Medal and Army Service Ribbon.
Cowboy gored to death by bull in New Year's Eve rodeo tragedyA US Army spokesperson told CBS News that Card enlisted in December 2002 and serves as a petroleum supply specialist. He has no combat deployments, the spokesperson confirmed.
However, Mr Galbreath said his military training would have provided a survival "skillset and mindset", which would have taught him how to "live in an environment that's not comfortable". Card is still an active member of the Reserves, and therefore has access to military bases across the country.
A neighbour described Card's home as being on a "compound" with his family, who are also gun fanatics. Liam Kent, who lives near Card in Bowdoin, said he knew the suspect and his relatives as "gun-toting enthusiasts" who lived in "basically a compound".
"They would shoot guns all the time, you could hear them every day after school. It was like clockwork," said Liam. He added he once saw Card "covered in blood with a gun on his back [and] a giant grin on his face" after going deer hunting.
Longtime neighbour Rick Gadden said Card was a keen hunter, who knows the area in great detail. He said: "He knows this area like the back of his hand, if he doesn't want to be found he won't. He's a hunter."
Card could have escaped on a jet ski
As authorities searched for Card, armoured tanks and SWAT teams were seen scouring a waterway entrance to the Androscoggin River in the early hours of Thursday morning. It came after Card's white Subaru Outback was found abandoned at a boat dock in Miller Park.
According to a spokeswoman, Card's 15-foot Bayliner boat is also missing with the US Coastguard on the hunt for it. Marine records also show that Card registered a 2019 Sea Doo jet ski in his name in June.
It has sparked fears that he could have used the jet ski to escape investigators after opening fire. Maine State Police aircraft were spotted searching a small area of the river in the early hours on Thursday in an attempt to track down Card.