Just 12 days after Kalief Browder celebrated his 22nd birthday on May 25, he wrapped an air-conditioner power cord around his neck and hung himself out the window of his mother's home in the Bronx.

Although he may not have left a suicide note, there is little doubt that he took his life in order to put an end to the pain, torture and agony that continued to haunt him after he spent three years in prison without a conviction.

In 2010, at the age of 16, Browder was arrested for allegedly stealing a backpack. He subsequently spent three years in New York City's Rikers Island prison, the second-largest jail system in the country. During his time, he was beaten by prison guards and inmates and spent more than two years in solitary confinement.

Instead of taking a taking a plea bargain and confessing to a crime that he insisted that he did not commit, Browder decided to have his case heard in court to prove his innocence, reports The New Yorker. As a result, that meant that he would have to spend time behind bars because his family could not afford to pay his hefty bail.

It took three years before a judge finally heard his case and then dismissed the charges. Kalief was released from prison at the age of 20 in June 2013, but the nightmare he lived through overwhelmed him and he struggled to reclaim his life.

Two years after his release, he committed suicide on June 6.

On Thursday, activists and mourners gathered at the Metropolitan Detention Center in Lower Manhattan in memory of Browder and rally support for a bill that could have kept the young man from spending years at an adult prison.

"Rikers wasn't a place for Kalief," said Carmen Perez, executive director of The Gathering for Justice, which is dedicated to ending youth incarceration, according to MSNBC. "It's not a place for the 10,000 teenagers currently residing in adult facilities across America."

The demonstrators held signs reading "Raise the Age," referring to a campaign to raise the age of criminal responsibility and expand pretrial diversion programs for juvenile offenders.

The proposal to "raise the age" is also backed a number of prominent New York officials, including Gov. Andrew Cuomo, New York City Mayor Bill de Blasio and Police Commissioner William Bratton.

According to a 164-page report published by the Governor's Commission on Youth, Public Safety, and Justice released, adolescents placed in adult jail facilities suffer increased risk of recidivism and suicide.

At the vigil, Browder's older brother also spoke publicly about his brother for the first time, praising him for fighting for his innocence.

"He stuck strong. He was strong until the very end. Three years on incarceration. To keep on saying that he's not guilty. To keep professing his innocence until the last day when they just let him go. As though their job is done. They did what they needed to. They killed another black man."