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(CNN) —  

Two bombs struck near the finish line of the Boston Marathon on April 15, 2013, killing three people and injuring more than 250 others. A fourth person, an MIT police officer, was killed three days later during the manhunt for the bombing suspects.

Here is a timeline of events, from the days leading up to the bombings to the day of the marathon, the manhunt, the aftermath and the judicial process. Information has been culled from law enforcement, court documents and news reports.

Tamerlan Tsarnaev, who was accused of the bombings, is dead. His brother, Dzhokhar Tsarnaev, was put on trial in the case. The timeline reflects the government’s case against Dzhokhar and the jury’s decision to convict and sentence him to death on some counts.

BEFORE THE BOMBINGS

Before April 15, 2013

Dzhokhar Tsarnaev downloads a digital copy of a book onto his Sony laptop. The foreword was written by Anwar al-Awlaki, who a federal indictment identifies as “a well-known al Qaeda propagandist.” This publication directs Muslims not to give their allegiance to governments that invade Muslim lands. Al-Awlaki was killed in a drone strike in Yemen in 2011.

Tsarnaev also downloads a publication by Abdullah Azzam, who is also known as “the Father of Global Jihad.” It advocates violence to terrorize enemies of Islam. A third downloaded publication glorifies martyrdom in the service of violent jihad.

He downloads a copy of Volume 1 of al Qaeda’s “Inspire” magazine, which includes an article, “Make a Bomb in the Kitchen of Your Mom,” and instructions on how to build IEDs using pressure cookers or sections of pipe, explosive powder from fireworks and shrapnel.

February 6, 2013

Tamerlan Tsarnaev buys 48 mortars containing approximately 8 pounds of low-explosive powder at a fireworks store in Seabrook, New Hampshire.

March 20, 2013

The Tsarnaev brothers rent two 9 mm handguns and buy 200 rounds of ammo at a firing range in Manchester, New Hampshire, and practice for about an hour.

April 14, 2013

Tamerlan Tsarnaev receives by mail electronic components to be used in making the IEDs. He had ordered them over the Internet.

Dzhokhar Tsarnaev opens a prepaid cell phone account under the name “Jahar Tsarni.”

THE BOMBINGS

April 15, 2013

2:39 p.m. – Two young men carrying backpacks turn off Gloucester Street onto Boylston Street near the final stretch of the Boston Marathon. One is wearing a black cap and the other a white cap turned backward. The young man in the black cap is later identified as Tamerlan Tsarnaev, 26, and the other as his brother, Dzhokhar, 19, both of Cambridge.

2:40 p.m. – Tamerlan Tsarnaev walks to the front of Marathon Sports on Boylston Street and places a backpack containing a pressure cooker bomb among the crowd gathered near the finish line. The Boston Marathon is in its fourth hour. Dzhokhar walks to the front of the Forum restaurant, about a block and a half away, and leaves a second backpack and pressure cooker bomb among the crowd.

2:48 p.m. – Dzhokhar calls Tamerlan on the prepaid cell phone and speaks with him briefly.

2:49 p.m. – Seconds after hanging up, Tamerlan Tsarnaev detonates the bomb in front of Marathon Sports, killing Krystle Marie Campbell and burning and maiming many others.

2:49 p.m. – About 12 seconds later, Dzhokhar sets off the second bomb in front of the Forum restaurant, killing Lingzi Lu and Martin Richard, and burning and maiming many others.

3:30 p.m. – Cab driver Khairullozhon Matanov, a friend of both brothers, calls Tamerlan and invites them to dinner, his treat, at a restaurant.

8:04 p.m. – Dzhokhar tweets, under his handle @J_tsar: “Ain’t no love in the heart of the city. Stay safe people”

April 16, 2013

Jeff Bauman, who lost both legs, gives the FBI a description of the man who dropped a backpack near him.

8:55 p.m. – Dzhokhar returns to campus at UMass-Dartmouth, swiping his ID. He and a friend go to the gym five minutes later.

April 17, 2013

1:43 a.m. – Dzhokhar tweets, “I’m a stress free kind of guy.”

A college friend, Dias Kadyrbayev, visits Dzhokhar that afternoon at his dorm room and notices that he has cut his hair short.

Kadyrbayev’s roommate, Azamat Tazhayakov, another student at UMass who is friendly with Dzhokhar, hangs out with him that evening in his dorm room until about midnight.

April 18, 2013

Dzhokhar Tsarnaev seems to be living the life of a normal college sophomore. He keeps his laptop and a backpack containing fireworks that had been emptied of powder in his dorm room. He drives Tazhayakov home to New Bedford after classes that afternoon.

5 p.m. – The FBI publishes surveillance photos of the bombing suspects on its website. They are immediately picked up by media around the world. The names of the suspects are not yet public.

5 to 6 p.m. – A third classmate, Robel Phillipos, who has known Tsarnaev since high school, calls Kadyrbayev as he drives home and tells him to watch the news because one of the bomb suspects looks familiar.

8:45 p.m. – Dzhokhar Tsarnaev responds to a text from Kadyrbayev, who notes the suspect looks like him: “LOL.” He sends a return text to Kadyrbayev, “You better not text me” and “If yu want yu can go to my room and take what’s there.”

Kadyrbayev, Tazhayakov and Phillipos go to the dorm room. Tazhayakov and Kadyrbayev take a backpack and laptop back to their New Bedford apartment. Kadyrbayev later tosses the backpack in a dumpster.

10 p.m. – At the family’s apartment in Cambridge, the Tsarnaev brothers grab five IEDs, a machete, a Ruger P95 9 mm semiautomatic handgun and ammunition for the Ruger. They drive Dzhokhar’s Honda Civic to the Massachusetts Institute of Technology campus in Cambridge.

10:25 p.m. – Sean Collier, an MIT police officer, is ambushed from behind and shot in the head at close range with the Ruger. The suspects attempt to take his service weapon. Tamerlan is allegedly the shooter.

11 p.m. – One of the brothers – police believe it was Tamerlan – points a gun at a man identified only as “D.M.,” threatens his life and carjacks his leased Mercedes ML350 SUV. “Did you hear about the Boston explosion?” he said, according to an affidavit. “I did that.” He pulled the magazine from his weapon and showed it was loaded. “I am serious,” he said. The brothers force D.M. to drive them to Watertown, where they retrieve a portable GPS device and other items from the Civic. They then order D.M. to drive to a gas station to fill the Mercedes’ gas tank. While searching for a gas station, they pull up to a Bank of America branch in Watertown Square and force D.M. to hand over his debit card and personal identification number. Dzhokhar uses the card to withdraw $800 from D.M.’s account.

THE MANHUNT

April 19, 2013

12:15 a.m. – D.M. escapes from the Mercedes, runs to another gas station across the street and calls 911. He says police can track the SUV because he left his iPhone in it. The brothers drive to Laurel Street and Dexter Avenue in Watertown, where police try to apprehend them.

12:43 a.m. – Dzhokhar and Tamerlan Tsarnaev engage in a gunbattle with police and use four of the five IEDs, including a pressure cooker bomb and pipe bombs.

12:50 a.m. – Tamerlan Tsarnaev, weakened by multiple gunshot wounds, is tackled by three Watertown police officers – Sgt. Jeffrey Pugliese, Sgt. John MacLellan and Officer John Reynolds. He struggles as they try to handcuff him.

Dzhokhar gets back into the Mercedes SUV and steers it directly at the three police officers. He barely misses Pugliese, who was attempting to drag Tamerlan to safety. Dzhokhar runs over his brother, “seriously injuring him and contributing to his death,” the indictment against him says.

Richard Donohue, a Massachusetts Bay Transportation Authority officer, is hit by friendly fire and nearly bleeds to death.

1:35 a.m. – Tamerlan is pronounced dead at Beth Israel Deaconess Medical Center. The cause: “traumatic injuries” of the head and torso. His fingerprints lead to identification of both bombing suspects.

Dzhokhar, also bleeding from multiple gunshot wounds, smashes his cell phones and abandons the Mercedes on Spruce Street in Watertown. He hides in a dry-docked boat, The Slipaway II, in a backyard in Watertown.

7 a.m. – Investigators release Dzhokhar Tsarnaev’s name and photo. Police begin a door-to-door search in Watertown, which is under a “shelter in place” order.

5 p.m. – Agents raid an apartment in New Bedford and question Dzhokhar’s classmates.

6 to 7 p.m. – The shelter in place order is briefly lifted. David Henneberry goes out to check on his boat and sees “a man covered with blood under the tarp.”

8:30 p.m. – Police announce they have a person they believe to be suspect Dzhokhar Tsarnaev cornered in the boat. They fire flash-bang grenades and their weapons and order him to come out with his hands up.

8:45 p.m. – Covered with blood, Tsarnaev emerges from the boat, lifting his shirt to show he is not armed.

PHOTO: Sean Murphy/Boston Magazine

8:46 p.m. – Boston police tweet “Suspect in custody. Officers sweeping the area. Stand by for further info.”

8:58 p.m. – Official word comes via Twitter from the Boston police: “CAPTURED!!! The hunt is over. The search is done. The terror is over. And justice has won. Suspect in custody.”

THE AFTERMATH

April 20, 2013

7:30 p.m. – Dzhokhar Tsarnaev is questioned by FBI agents at the hospital. The first round lasts about 12 hours, with breaks. He is not read his Miranda rights or given access to a lawyer.

April 21, 2013

5:35 p.m. – Second round of questioning continues until 9 a.m. the next day, when Tsarnaev is appointed a lawyer.

A criminal complaint is filed under seal alleging use of a weapon of mass destruction and malicious destruction of property.

According to documents filed later by his lawyers, during questioning Tsarnaev was intubated and unable to speak, but communicates by writing on a notepad. His lawyers say he was heavily sedated, in pain, and asked repeatedly to be left alone. His injuries include multiple gunshot wounds that pierced the base of his skull, mouth and vertebrae. He required emergency surgery.

He says there are no other suspects at large, and no other bombs. From a defense motion: “In all, he wrote the word ‘lawyer’$2 10 times, sometimes circling it. At one point, he wrote, “I am tired. Leave me alone. I want a l[illegible].” His pen or pencil then trails off the page, suggesting that he fell asleep, lost motor control, or passed out. At least five other times in these pages, he begged the agents to leave him alone and to let him sleep. He also wrote, “I’m hurt,” “I’m exhausted,” and “Can we do this later?” At one point, he wrote, “You said you were gonna let me sleep.” Another note reads, “I need to throw up.”

Agents search Dzhokhar’s dorm room at Pine Dale Hall on the UMass-Dartmouth campus; they find the dark jacket and white hat seen on the surveillance video. They also find some BBs and gunpowder on the floor and windowsill.

Agents search the New Bedford apartment and continue to question Dzhokhar’s classmates.

Tsarnaev gets to see a lawyer at 9 a.m. on April 22 and is arraigned at his bedside.

May 1, 2013

Three college friends of Dzhokhar Tsarnaev, all 19, are accused of helping him after the bombing. Federal prosecutors say Azamat Tazhayakov, Dias Kadyrbayev and Robel Phillipos took a laptop and backpack from Tsarnaev’s dorm room to throw investigators off his trail. Tazhayakov and Kadyrbayev are charged with obstruction of justice. Phillipos, an American citizen, is charged with lying to federal agents.

May 22, 2013

An FBI agent shoots and kills Ibragim Todashev in Orlando, Florida, while questioning him about his relationship with Tamerlan Tsarnaev. Cell phone records connect the two. Todashev tells the FBI that Tamerlan told him he participated in a drug-related triple homicide. The victims’ throats were slashed and marijuana had been sprinkled over the bodies.

THE COURTS

July 10, 2013

Dzhokhar Tsarnaev pleads not guilty to 30 federal counts related to the Boston Marathon bomb attacks.

July 21, 2013

A jury finds Azamat Tazhayakov guilty of obstructing justice and conspiring to obstruct justice in connection with the removal of a backpack with potential evidence from Tsarnaev’s dorm room after the bombings.

January 30, 2014

Federal prosecutors file notice the government will seek the death penalty against Dzhokhar Tsarnanaev

May 30, 2014

Khairullozhon Matanov, a cab driver from Quincy, Massachusetts, is charged with destroying information on his computer, lying to federal agents and impeding the investigation. Matanov was a friend of the Tsarnaev brothers and ate dinner with them after the bombing.

August 2, 2014

Kadyrbayev pleads guilty to obstructing justice. As part of the plea deal, prosecutors will recommend a seven-year sentence and Kadyrbayev, a Kazakh national, agreed to be deported when he is released.

October 28, 2014

Phillipos is convicted of two counts of lying to federal agents.

January 5, 2015

Jury selection begins with 1,373 prospective jurors receiving and filling out questionnaires.

January 12, 2015

Matanov, the cab driver charged with impeding the investigation and destroying evidence in his computer, files notice that he plans to plead guilty. There is speculation he has made a deal to testify.

January 26, 2015

Opening statements originally scheduled, but picking an impartial jury that can consider the death penalty is taking longer than anticipated.

February 25, 2015

Judge George O’Toole, along with the prosecution and defense teams, settle on a pool of 70 jury prospects after questioning 256 people over 21 days of individual interviews.

Also, the U.S. Supreme Court issues a ruling in an unrelated case involving destruction of evidence that could affect potential testimony against Tsarnaev.

March 3, 2015

A jury of eight men and 10 women – 12 primary jurors and six alternates – is selected. Jurors include a house painter eager to “serve my country,” a man in his 20s who is Baha’i and speaks Farsi, and a water department employee who says he thinks the death penalty would be “the easy way out.”

March 4, 2015

The trial against Dzhokhar Tsarnaev begins in federal court in Boston.

The lead prosecutor opens his statements to the jury with a description of the explosives.

“It was the type of bomb favored by terrorists because it’s designed to tear people apart and create a bloody spectacle,” William Weinreb told jurors.

Prosecution witnesses recount the terror attack.

“I was really scared,” said Karen McWatters, formerly Karen Rand, “and I remember screaming for someone to help us. Everybody was screaming, everybody was screaming for help. It seemed like a long time before help got to us, but it probably wasn’t.”

March 31, 2015

The defense takes less than two days to present only four witnesses on Tsarnaev’s behalf. This contrasts to how the prosecution spent a month on calling more than 90 witnesses before the jury.

The defense has always conceded Tsarnaev’s involvement in the bombing, but courtroom observers are surprised by the defense’s presentation, finding the moment anti-climatic and describing it as “limp,” “lame,” and even “weak.

The defense case – presented by Judy Clarke, David Bruck, Miriam Conrad and William Fick – blamed the extremist influence of the defendant’s older, dead brother for the bombing.

Defense witnesses testified about the bomb-making materials and the jihadist literature. They put all of them in Tamerlan’s hands. The militant material was traced to Tamerlan’s laptop hard drive – although it also was on Jahar’s laptop – and to a mystery thumb drive. The dates of the computer file transfers roughly coincide with Tamerlan’s visit to Russia.

Tsarnaev doesn’t take the stand in his own defense. He is not required to.

April 6, 2015

The jury hears closing arguments from the prosecution and defense.

“The defendant brought terrorism into the backyards and main streets,” Assistant U.S. Attorney Aloke Chakravarty said. “The defendant thought that his values were more important than the people around him. He wanted to awake the mujahideen, the holy warriors, so he chose Patriots Day, Marathon Monday,” a time for families to gather and watch the marathon.

The defense said that Tsarnaev, who was 19 and flunking out of college at the University of Massachusetts, Dartmouth, fell under the sway of his older, more radicalized brother.

“It was Tamerlan,” defense attorney Clarke tells the jury. “If not for Tamerlan, it would not have happened.”

April 8, 2015

Guilty is the jury’s verdict after deliberating 11.5 hours.

The jury finds Tsarnaev guilty of all 30 counts. Tsarnaev, his face a blank, stands with his head bowed and his hands clasped.

He is now eligible for the death penalty.

April 21, 2015

The jury begins hearing testimony in a new phase, one to determine whether Tsarnaev should be sentenced to death or to life in prison.

Survivors speak of the bombing’s impact on their lives.

When the first of the two bombs went off, Gillian Reny, a senior in high school, was standing near the woman she came to know was Krystle Campbell.

“There was a complete, utter chilling silence and then chaos. Chaos like I’d never seen and never hope to see again,” she says. The force of the blast knocked her to the ground. When she looked around, she saw blood and muscle everywhere. Her shin bone had snapped and was protruding.

“Muscle was everywhere. It was the most horrifying image I could imagine. Just seeing that on my own body,” she says, and begins to cry. “I remember looking around and it just seemed like there were bodies everywhere, blood everywhere.”

Doctors saved Reny’s leg.

April 23, 2015

The prosecution rests in the death penalty phase.

April 27, 2015

The defense begins to present its case and asks the jury to spare Tsarnaev from the death penalty.

Instead, the jury should sentence him to life in prison, defense attorneys say.

Sending Tsarnaev to prison for the rest of his life would bring years of punishment and rob him of martyrdom, the defense argues.

“We have seen more pain and more horror and more grief in this courtroom than any of you would have thought possible,” attorney Bruck says.

“No punishment could ever be equal to the terrible effects of this crime on the survivors and the victims’ families,” he says. “There is no evening of the scales. There is no point of trying to hurt him as he hurt because it can’t be done. All we can do, all you can do is make the best choice.”

May 13, 2015

The jury begins deliberations after hearing attorneys’ closing arguments.

The prosecution says Tsarnaev is a remorseless terrorist worthy of the death penalty, but the defense says he was repentant and deserved to be spared execution.

“The defendant knew what kind of hell was going to be unleashed,” prosecutor Steve Mellin says.

Defense attorney Clarke counters: “We’re asking you to choose life. Yes, even for the Boston Marathon bomber.”

May 15, 2015

Tsarnaev is sentenced to death.

CNN’s Michael Martinez contributed to this report.