(AP) — Key moments related to the search for the Boston Marathon bombing suspects, based on reports from the Middlesex County district attorney, Massachusetts State Police, and Boston police.

— At 5:10 p.m. Thursday, investigators of the bombings release photographs and video of two suspects. They ask for the public’s help in identifying the men.

— Around 10:20 p.m., shots are fired on the campus of the Massachusetts Institute of Technology in Cambridge, just outside Boston.

— At 10:30 p.m., an MIT campus police officer who was responding to a disturbance is found shot multiple times in his vehicle, apparently in a confrontation with the Boston Marathon bombing suspects. He is later pronounced dead.

— Shortly afterward, two armed men reportedly carjack a Mercedes SUV in Cambridge. A man who was in the vehicle is held for about a half hour and then released unharmed at a gas station on Memorial Drive in Cambridge.

— Police soon pursue the carjacked vehicle in Watertown, just west of Cambridge.

— Some kind of explosive devices are thrown from the vehicle in an apparent attempt to stop police. The carjackers and police exchange gunfire. A transit police officer is seriously injured. One suspect, later identified as Suspect No. 1 in the marathon bombings, is critically injured and later pronounced dead.

— Authorities launch a manhunt for the other suspect.

— Around 1 a.m. Friday, gunshots and explosions are heard in Watertown, just outside Boston. Dozens of police officers and FBI agents converge on a Watertown neighborhood. A helicopter circles overhead.

— Around 4:30 a.m., Massachusetts state and Boston police hold a short outdoor news briefing. They tell people living in that section of eastern Watertown to stay in their homes. They identify the carjackers as the same men suspected in the marathon bombings. Overnight, police also release a photograph of a man believed to be Suspect No. 2, apparently taken from store video earlier in the evening at a 7-Eleven convenience store in Cambridge. He is wearing a grey hoodie-style sweatshirt.

— Around 6:35 a.m., The Associated Press reports that the bomb suspects are from a Russian region near Chechnya and lived in the United States for at least one year.

— Around 6:45 a.m., The Associated Press identifies the surviving Boston bomb suspect as Dzhokhar A. Tsarnaev, 19, who has been living in Cambridge, Mass.

— Around 8:40 a.m., a U.S. law enforcement official and the uncle of the suspects confirm that the name of the slain suspect is Tamerlan Tsarnaev, Dzhokhar Tsarnaev’s older brother.

 

A July trial in Nebraska has been scheduled for a Kansas fugitive who’s accused of firing at officers during a vehicle chase in southeast Nebraska.

33-year-old Michael Engstrom, of Topeka, Kan., pleaded not guilty earlier this week to several felony counts in Johnson County District Court.

His wife, Jamie Engstrom, pleaded guilty to felony child abuse. Prosecutors dropped several charges connected to the Feb. 13 chase in exchange for Jamie Engstrom’s plea. Authorities say the child abuse charge was filed because Jamie Engstrom had placed a 14-year-old child in harm’s way. Officers discovered after the chase that the child was in the Engstroms’ car.

Both Engstroms have been charged with murder in the slaying of a Topeka man earlier on Feb. 13.

Two Nebraska men have been charged in separate federal indictments with child pornography counts.

The U.S. Attorney’s office for Nebraska says 56-year-old James Haugh, of Grand Island, and 26-year-old Michael Nguyen, of Lincoln, were indicted earlier this week.

Both Haugh and Nguyen each face two counts — one of receiving and distributing child pornography and one of possessing child pornography.

Federal prosecutors say Haugh received and distribute child porn on different occasions from Jan. 3, 2009, to Dec. 28, 2012. Nguyen is accused of receiving and distributing child porn from Jan. 17 to March 22.

If convicted, each faces up to 30 years in federal prison.

UPDATE 4/19 07:54am

A U.S. law enforcement official and the uncle of the suspects in the Boston Marathon bombings are confirming that the name of the second suspect is Tamerlan Tsarnaev, the older brother of Dzhokhar A. Tsarnaev, 19. Tamerlan Tsarnaev was killed in a gun battle with police in Massachusetts overnight.

Three law enforcement officials, speaking on condition of anonymity due to the sensitivity of the ongoing investigation, confirmed the bomb suspects were brothers. One of the officials and the men’s uncle confirmed the identity of Tamerlan Tsarnaev.

The uncle, Ruslan Tsarni of Montgomery Village, Md., told The Associated Press that the men lived together near Boston and have been in the United States for about a decade. They traveled here together from the Russian region near Chechnya.

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Police are locking down some neighborhoods in Boston and its western suburbs as they search for the remaining suspect in the marathon bombings.

Authorities urged residents in Watertown, Newton, Waltham, Belmont, Cambridge, Arlington and the Allston-Brighton neighborhoods of Boston to stay indoors. All mass transit was shut down.

At least a quarter of a million people live in those suburbs. Many people in the city of Boston and surrounding areas rely on the Massachusetts Bay Transit Authority to get to work.

The announcement Friday morning comes hours after the killing of one suspect, known as the man in the black hat from marathon surveillance footage. The man in the white hat is on the loose and police are calling him a “terrorist” who came here “to kill.”