Boston Marathon bombings and the aftermath

Joe Kebartas holds a sign outside the John Joseph Moakley Federal Courthouse on the opening day of the trial of suspected Boston Marathon bomber Dzhokhar Tsarnaev.  (CJ GUNTHER / EPA)

A police dog sniffs near news cameras outside of the entrance to the John Joseph Moakley United States Courthouse during the first day of the Dzhokhar Tsarnaev trial on March 4, 2015 in Boston.  (Scott Eisen / Getty Images)

Members of a police honor guard lead a column of law enforcement officials into a memorial service for fallen Massachusetts Institute of Technology police officer Sean Collier, in Cambridge, Mass.  (Steven Senne / Associated Press)

A Revere, Mass. police captain holds his cap while entering a memorial service for fallen MIT police officer Sean Collier, in Cambridge, Mass.  (Steven Senne / Associated Press)

A woman and two children gather at the site of the first bombing near the finish line of the Boston Marathon on Boylston Street in Boston.  (JUSTIN LANE / EPA)

Supporters hang an American flag in a tree across the street from St. Joseph’s Church before the start of the funeral for bombing victim Krystle Campbell in Medford, Mass.  (CJ Gunther / EPA)

A sign in memory of bombing victim Krystle Campbell in Medford Square, near where her funeral was scheduled to be held Monday morning.  (CJ Gunther / EPA)

Teamster Jack Colamaria shows his respects near the site of funeral services for 29-year-old Krystle Campbell.  (Mario Tama / Getty Images)

The funeral procession passes through the town of Medford, Mass., for 29-year-old Krystle Campbell, who was one of three people killed in the Boston Marathon bombings.  (Mario Tama / Getty Images)

Holly Holland of St. Louis hugs her daughter Katie while visiting a makeshift memorial in Boston.  (Steven Senne / Associated Press)

Rabbi Howard Berman of Central Reform Temple participates in an interfaith memorial service near a makeshift memorial for victims of the Boston Marathon bombings.  (Kevork Djansezian / Getty Images)

Nurse practitioner Maureen Quaranto, who treated victims of the Boston Marathon bombings in Tent A, wears her Boston Marathon jacket during Mass at the Cathedral of the Holy Cross on the first Sunday after the marathon bombings.  (Mario Tama / Getty Images)

Law enforcement investigators continue collecting and processing evidence at the shooting scene near a boat where bombing suspect Dzhokhar Tsarnaev was hiding from police and eventually caught on Franklin Street in Watertown, Mass.  (Kevork Djansezian / Getty Images)

An FBI investigator wearing white overalls stands inside the boat where the bombing suspect was hiding from police on Franklin Street in Watertown, Mass. A manhunt for suspect Dzhokhar A. Tsarnaev, 19, ended Friday after he was apprehended on the boat. His brother Tamerlan Tsarnaev, 26, the other suspect, was shot and killed after a car chase and shootout with police.   (Kevork Djansezian / Getty Images)

People on Newbury Street walk past crime scene investigators, Boston police officers and military personnel near the scene of the Boston Marathon bombings.  (Mario Tama / Getty Images)

Before the game at Fenway Park, David Ortiz of the Boston Red Sox speaks during a pregame ceremony in honor of the marathon bombing victims.  (Jim Rogash / Getty Images)

A boy contemplates a street memorial on Boylston Street, the scene of two explosions that killed three people Monday near the Boston Marathon finish line, as Bostonians began returning to normal life on the morning after the capture of the second of two suspects wanted in the bombings.   (Timothy A. Clary / AFP/Getty Images)

A carpet of flowers, poster and personal objects -- along with three crosses for the victims for the three victims who died -- fill a street memorial near the Boston Marathon finish line.  (Michael Reynolds / EPA)

A television image shows Dzhokhar Tsarnaev, a suspect in the Boston Marathon bombing, straddling the side of the boat where he was found hiding Friday in Watertown, Mass.  (CBS News / AFP/Getty Images)

This still frame from video shows Boston Marathon bombing suspect Dzhokhar Tsarnaev visible through an ambulance after he was captured in Watertown, Mass., Friday.  (Robert Ray / Associated Press)

Investigators scour the area for evidence Saturday at the scene where Boston Marathon bombing suspect Dzhokhar Tsarnaev was captured after a standoff with police Friday night.  (Matt Rourke / Associated Press)

Boston-area law enforcement officers are recognized during a tribute to victims of Monday’s bombing before Saturday’s Major League Baseball game between the Boston Red Sox and the Kansas City Royals at Fenway Park.  (Jim Rogash / Getty Images)

More than 2,000 miles from Boston, a bomb squad truck is a conspicuous presence Saturday near the starting line of the Salt Lake City Marathon. Security has been dramatically increased at sporting events across the country in the wake of Monday’s bombings of the Boston Marathon.  (George Frey / Getty Images)

Residents pose with an officer after the capture of Boston Marathon bombing suspect Dzhokhar Tsarnaev is announced. About 200 people poured onto Hemingway Street in Boston’s Fenway neighborhood to cheer. The search for the 19-year-old suspect ended when he was found in a boat stored in a Watertown, Mass., backyad. His brother, Tamerlan Tsarnaev, 26, was killed during a firefight with police. The bombing near the finish line of the marathon killed three people and wounded at least 170.   (Kayana Szymczak / Getty Images)

Residents of Boston’s Fenway neighborhood poured into the streets to celebrate the end of the manhunt for bombing suspect Dzhokhar Tsarnaev, 19. Much of the city was locked down on Friday while the suspect was at large.  (Kayana Szymcza / Getty Images)

People in Boston’s Fenway neighborhood, many of whom were locked in their homes while a bombing suspect was on the loose, pour onto the streets to celebrate the man’s capture.   (Kayana Szymczak / Getty Images)

Residents in Watertown, Mass., who were told to stay locked in their homes during the manhunt for a Boston Marathon bombing suspect, celebrate after the man’s arrest.   (John Wilcox / McClatchy-Tribune)

A police officer is cheered by crowds after news came of the arrest of a Boston Marathon bombing suspect. Dzhokhar Tsarnaev, 19, was found hiding in a boat in a Watertown, Mass., backyard after a after a manhunt that left the city virtually paralyzed.   (Julio Cortez / Associated Press)

Police officers and SWAT team members celebrate after the capture of 19-year-old bombing suspect Dzhokhar Tsarnaev in Watertown, Mass. The manhunt for the Boston Marathon bombing suspect ended with his capture in a boat on residential property. The suspect’s brother, Tamerlan Tsarnaev, 26, died in a firefight with police early Friday.   (Mario Tama / Getty Images)

Police officers guard the entrance to Franklin Street in Watertown, Mass., where the surviving Boston Marathon bombing suspect was believed to be hiding. Dzhokhar Tsarnaev was taken into custody.  (Matt Rourke / Associated Press)

People watch as police arrive in Watertown, Mass., where shots were reportedly fired and Boston Marathon bombing suspect Dzhokhar Tsarnaev, 19, was reportedly taken into police custody.  (Mario Tama / Getty Images)

Members of a police S.W.A.T. team run to the Watertown, Mass., area where Boston Marathon bombing suspect Dzhokhar Tsarnaev, 19, was believed to be hiding.  (Spencer Platt / Getty Images)

Watertown resident Rosie Meyer, who said she heard gunshots, watches the police response in the Boston suburb.   (Mario Tama / Getty Images)

Law enforcement officers approach the area where suspect Dzhokhar Tsarnaev was believed to be hiding in Watertown, Mass.  (Darren McCollester / Getty Images)

SWAT team members search for one remaining suspect at a residential building in Watertown, Mass.  (Mario Tama / AFP / Getty Images)

Police patrol through a neighborhood in Watertown, Mass., while searching for a suspect in the Boston Marathon bombings.  (Charles Krupa / Associated Press)

Image released by the FBI of Dzhokhar Tsarnaev, 19, a suspect in the Boston Marathon bombing.  (Handout / Getty Images)

Police take cover as they surround a home while searching for a suspect in the Boston Marathon bombings in Watertown, Mass.  (Charles Krupa / Associated Press)

Evacuated neighbors wait several blocks away as FBI agents prepare to enter an apartment building on Norfolk Street in Cambridge, Mass., reported to be the residence of the two suspects who may have bombed the Boston Marathon.  (Matt Campbell / EPA)

FBI agents and police evacuate neighbors as they prepare to enter an apartment building on Norfolk Street in Cambridge, Mass.  (Matt Campbell / EPA)

A woman attends a vigil Tuesday at Boston’s Garvey Park for 8-year-old Martin Richard of Dorchester, who was killed by an explosion near the finish line of the Boston Marathon.   (Jared Wickerham / Getty Images)

Participants at a candlelight vigil Tuesday for Boston Marathon bombing victim Martin Richard, 8, include residents of his Dorchester neighborhood.   (Jared Wickerham / Getty Images)

Lizzie Lee, 56, of Lynwood, Wash., who was participating in her first Boston Marathon, is among those attending a vigil Tuesday at Boston Common for the victims of Monday’s bombing attack.  (Julio Cortez / Associated Press)

The congregation stands during a candlelight interfaith service Tuesday at Arlington Street Church in Boston for bombing victims.  (Stan Honda / AFP/Getty Images)

Emma MacDonald, 21, center, cries at the Boston Common vigil Tuesday for the victims of the marathon bombings.   (Julio Cortez / Associated Press)

A Boston police officer morning stands at a barricade Tuesday blocking off the scene of Monday’s twin bombings near the finish line of the Boston Marathon. The explosions killed three people and injured scores.  (Spencer Platt / Getty Images)

Unused thermal blankets meant for marathon participants are piled near the scene of a twin bombings at the Boston Marathon.  (Spencer Platt / Getty Images)

A police officer stands near the scene of Monday’s twin bombings at the Boston Marathon.  (Spencer Platt / Getty Images)

The unfinished meals of fleeing customers are left on tables at an outdoor restaurant near the scene of twin bombings at the Boston Marathon.  (Spencer Platt / Getty Images)

Injured people lie on the ground near the Boston Marathon finish line after an explosion Monday.  (Ken McGagh / Associated Press)

As Boston Marathon runners walk by, SWAT team members stand guard near the finish line.  (Winslow Townson / Associated Press)

A man comforts an injured woman on the sidewalk after the first explosion.  (Boston Globe / Boston Globe via Getty Images)

In this image from video provided by WBZ-TV, spectators and participants scramble away from what authorities described as two explosions at the finish line of the Boston Marathon.  (WBZ-TV / Associated Press)

Medical workers aid injured people at the finish line of the Boston Marathon following two explosions.  (Charles Krupa / Associated Press)

Medical workers take the injured across the finish line after explosions at the Boston Marathon.  (Charles Krupa / Associated Press)

Medical responders rush a man injured in the explosions past the finish line of the Boston Marathon.  (Charles Krupa / Associated Press)

A Boston police officer clears Boylston Street after explosions at the finish line of the 2013 Boston Marathon.  (Charles Krupa / Associated Press)

A man is loaded into an ambulance after he was injured by one of the two explosions.   (Jim Rogash / Getty Images)

Runner John Ounao cries when he meets up with friends after the explosions.  (John Mottern / AFP/Getty Images)

Medical workers aid an injured man.  (David L. Ryan / Associated Press)

A runner embraces another woman on the Boston Marathon route near Kenmore Square after two explosions.  (Alex Trautwig / Getty Images)

Medical personnel work outside the medical tent in the aftermath of two blasts near the finish line of the Boston Marathon.  (Elise Amendola / Associated Press)

A runner reacts near Kenmore Square after two bombs exploded near the finish line of the Boston Marathon.  (Alex Trautwig / Getty Images)