Gotcha!': The First Pictures of Alleged Boston Bomber In Custody Surface

Police captured 19-year-old Boston bombing suspect Dzhokhar Tsarnaev on Friday night following a nearly 24-hour manhunt. He had been hiding in a boat parked in a backyard.

The bloody endgame came four days after the bombing and just a day after the FBI released surveillance-camera images of two young men suspected of planting the pressure-cooker explosives that ripped through the crowd at the marathon finish line, killing three people and wounding more than 180.

The first images of Dzhokhar Tsarnaev, who was alive but in serious condition, began to emerge late Friday night:

This still frame from video shows Boston Marathon bombing suspect Dzhokhar Tsarnaev visible through an ambulance after he was captured in Watertown, Mass., Friday, April 19, 2013. A 19-year-old college student wanted in the Boston Marathon bombings was taken into custody Friday evening after a manhunt that left the city virtually paralyzed and his older brother and accomplice dead. (AP Photo/Robert Ray)

(AP Photo/Robert Ray)

(AP Photo/Robert Ray)

(AP Photo/Robert Ray)

And Twitter user @Hossenator (Edward Fitzgerald) tweeted out the following photo allegedly showing the suspect with the caption "Gotcha!". It's unclear if he is a law enforcement official. (​Updat​e:​ The Bureau of Alcohol, Tobacco, Firearms and Explosives confirmed to ABC News that the photo shows one of their medics rendering assistant to the suspect.)

(Twitter)

Early Friday morning, 26-year-old Tamerlan Tsarnaev was killed in a ferocious gun battle and car chase during which he and his younger brother hurled explosives at police from a stolen car, authorities said. The younger brother managed to escape.

During the getaway attempt, the brothers killed an MIT policeman and severely wounded another officer, authorities said.

Investigators have not indicated motive for their killing spree.

The Associated Press contributed to this report.