CONEY ISLAND, Brooklyn (WABC) -- A jury has found a Brooklyn teenager guilty of killing an NYPD officer by setting a mattress on fire in 2014.
The jury found Marcel Dockery guilty on all three counts he was facing -- murder, assault and arson.
The verdict came the same day the jury got the case. Attorneys made their closing arguments Thursday morning, and the jury announced it had a verdict at about 5 p.m.
NYPD officers came to court to show support:
Jurors were charged with deciding if Dockery set a mattress on fire in the hallway of a building in Coney Island in 2014. Officer Dennis Guerra was killed in the fire. His partner, Rosa Rodriguez, has permanent lung damage.
The jury submitted two notes to the judge Thursday afternoon:
"With respect to our unanimous verdict, we the jury would like to express our sincere feeling that the defendant didn't not mean to harm anyone as a result of his actions."
"While sentencing did not play a role, we hope that leniency can be shown."
"We the jury have reached a verdict."
Dockery is now facing a sentence of 25 years to life in prison.
Last week, a videotaped confession from Dockery was played in which he told police he lit the corner of the mattress on fire because he was bored while waiting for his cousins, who also live in the building, to open their door.
Just two hours into deliberations Thursday afternoon, jurors had several questions, one about exactly when Dockery was read his rights back in April 2014, when the then 16-year-old was arrested on charges of starting a fire on the 13th floor of the apartment building.
"I was just bored of waiting, so I walked down and started burning the edge of the mattress, but I wasn't doing it to like do anything wrong, I was just bored," he said.
The alleged videotaped confession was called into question when the now 18-year-old took the stand in his own defense Tuesday, saying detectives threatened to evict his family if he didn't fess up.
But Dockery testified that he knocked on doors to let neighbors know about the fire.
"I thought I blew it out all the way once I start walking down, and I start knocking on the door the whole mattress is on fire," he said. ('And now you see flames?') "Yeah and I got scared."
Jurors also asked to see surveillance video again, showing Officers Guerra and Rodriguez responding to the fire just before they were overcome by smoke.
Guerra died three days later. Rodriguez spent six weeks in the hospital.
Patrick Lynch, president of the city's rank-and-file police union, the Patrolmen's Benevolent Association, said jurors reached a "difficult but just decision." He said Guerra's family was satisfied with the verdict, but that it wouldn't bring their loved one home.
"So this doesn't fix everything," he said. "But it does bring justice and it does send a message that you cannot kill a New York City police officer no matter how that's done."
(Some information from the Associated Press)