10 dumb things Boston Marathon bombing suspects Tamerlan and Dzhokhar Tsarnaev did after the attack

Using improvised bombs made from pressure cookers bought at Macy’s, the Russian-born brothers detonated two devices at the Boston Marathon, killing three people and wounding more than 250.

But their behaviour during the attack and after begs the question: What were they thinking?

Three days after the outrage, the pair were involved in a dramatic gun battle with police on the streets of Boston. Tamerlan was gunned down, then run over by his younger brother as he fled. The 26-year-old died at the scene.

Dzhokhar, 19, was found several hours later hiding in a boat in a suburban back yard. he allegedly tried to kill himself but failed.

Investigators are unsure if the brothers – described by US Vice-President Joe Biden as “two twisted, perverted, cowardly knockoff jihadists” – were part of wider terror cell in the US.

If their actions are anything to go by, they might also qualify as “strangest”.

Here’s 10 things they did that just don’t make sense.

1. Wear a baseball cap backward and no sunglasses.

As CCTV footage shows, Dzhokhar made little effort to prevent cameras from capturing his face on the day of the bombings, making him easy to identify when the FBI released security camera images. Tamerlan, in contrast, wore dark glassees and had his cap on the right way, partially concealing his face.

Dzhokhar Tsarnaev TamerlanTsarnaev

Dzhokhar Tsarnaev and TamerlanTsarnaev pictured at the Boston Marathon. Dzhokhar made no attempt to hide his identity from any cameras. (AP Photo/FBI) Source: AP

2. Not react to the explosions.

In the days after the bombings, investigators studied all available photos and surveillance videos of the blast area searching for abnormal reactions. The complaint filed in federal court this week specifically cites Dzhokhar’s reaction to the first explosion as a giveaway.

“Approximately 30 seconds before the first explosion, Suspect 2 (Dhzokhar) lifts his phone to his ear as if the is speaking on his cell phone, and keeps it there for approximately 18 seconds,” the FBI’s complaint states.

“A few seconds after he finishes the call, the large crowd of people around him can be seen reacting to the first explosion. Virtually every head turns to the east (towards the finish line) and stares in that direction in apparent bewilderment and alarm.

“Bomber Two, virtually alone among the individuals… appears calm. He glances to the east and then calmly but rapidly begins moving to the west.”

Boston Marathon Explosions Photo Package

In this image from video provided by WBZ TV, a bomb explodes near the finish line of the Boston Marathon in Boston on Monday, April 15, 2013. (AP Photo/WBZTV) Source: AP

3. Leave their car at the repair shop, then go pick it up.

The Wall Street Journal reported that Dzhokhar stopped by a mechanics in Watertown on Tuesday to pick up the Mercedes he’d brought in for repairs.

“The younger brother was jittery, said Gilberto Junior, who works at the shop. “He was biting his nails, and when he was talking to me, his legs were like this,” Mr. Junior said, shaking one leg. “He said, ‘I need the car now. I need the car right now.’ ”

4. Stay in Boston.

The second bomb exploded at 2:49pm (Boston time) last Monday. It wasn’t until 10.49pm Thursday (Boston time) that the brothers carjacked a Mercedes.

What did they do in the interim three days? Go to the gym, check in on their broken car, and, in Dzhokhar’s case, go to a party on the University of Massachusetts Dartmouth campus.

During the three-day window in which their involvement was unknown, they made no attempt to flee, and when they did finally make a run for it, they stuffed it up.

5. Run out of cash.

When Dzhokhar carjacked the Mercedes on Thursday night (Boston time) and took their hostage, he and his brother needed cash badly.

Using their victim’s ATM card and PIN number, they withdrew $800, before they reached the account limit. Holding up a stranger for money suggests no planning went into any getaway. The fact they hadn’t budgeted and had to resort to such desperate measures helped alert them to the authorities.

6. Not understand how ATMs work.

After reaching the daily withdrawal limit at one machine, the Tsarnaevs decided to try their luck at two different machines.  Did they not realise ATMs are part of an interconnected system? It was while they were hunting a working ATM that they ended up, coincidentally, at a 7-11 in Cambridge around the same time it was the scene of an armed robbery, and were spotted on the store security camera.

7. Confess to the hostage.

According to the FBI’s complaint, when Dzhokhar got into the Mercedes, he immediately told the driver, “Did you hear about the Boston explosion? I did that.” That meant the brothers’ cover would be immediately blown if the driver escaped.  Guess what happened next ….

8. Stop for a snack and allow hostage to escape.

The Los Angeles Times reported that the hostage escaped after the brothers stopped at a petrol station to buy snacks. The unidentified driver fled to another petrol station to call police. He was able to describe his car, the number plate and his captors. From there, the manhunt was on in earnest.

9. Keep the hostage’s phone.

Maybe they panicked, but for some reason, the brothers continued on in the carjacked Mercedes without their hostage but they did have his phone, which allowed police to track their location via GPS, accordng to Time magazine.

Police with guns drawn during the dramatic manhunt for the Tsarnaev brothers three days after the Boston Marathon bombing. Picture: Mario Tama/Getty Images Source: Getty Images

10. Bring a BB gun.

Maybe not crucial to the case, but the weapons used by the two suspects were, according to police: a pressure-cooker bomb, seven improvised explosive devices (IEDs), an M4 carbine, two handguns, and a BB gun – which is an airgun originally sold as a toy in the US. Why bring a  BB gun?