NEW YORK (CNN) -- A New York City police offer has pleaded not guilty in the shooting death of an unarmed 18-year-old who police say they chased into his home in February.

According to the Bronx District Attorney's Office, a grand jury returned an indictment against Officer Richard Haste, 31, charging him with one count of first-degree manslaughter and one count of second-degree manslaughter.

Haste was released on $50,000 bail, according to court documents.

The indictment alleges that Haste acted "recklessly" and ultimately killed Ramarley Graham while "acting with intent to cause serious physical injury ... by shooting him."

Haste's attorney says he shot Graham because he believed the teenager had a gun, but no weapon was ever found.

"We can't keep killing our kids," said Constance Malcolm, Graham's mother. "It has to stop. Something has to come out of this."

The charges against Haste stem from an incident in the Bronx on February 2, when, police say, investigators observed a young man now believed to be Graham acting suspiciously. When police approached, they say, the man fled, eventually running into a three-family home on East 229th Street in the Bronx.

Police say investigators pursued the young man into his house, where a struggle occurred. Haste fired one shot and hit Graham in the chest as he barricaded himself in the bathroom.

Graham's family said he was shot as his grandmother and his 6-year-old brother looked on.

"Clearly, my client was in the state of mind he was going to be shot," said Haste's attorney, Stuart London. "He was told by other officers they had seen a weapon in (Graham's) waistband. He's allowed to rely on the accuracy of the information from officers he works with. It's how they survive, ensure their own safety."

London continued, "My client told the decedent to show him his hands, and he refused." He said Graham then put his hands near his waistband and made a move toward Haste.

"Had the decedent acquiesced at any time, we wouldn't be in court today," London said.

Jeff Endin, an attorney for Graham's family, said Haste and his fellow officers were out of line.

"They never should have been in the building; he never should have been in that apartment."

Endin isn't the only one saying police have been overzealous. The incident has inspired vigils, protests and rallies in the community, alleging the use of excessive force and calling for investigations.

"The city has to deal with this death and justice for this family," said the Rev. Al Sharpton, the civil rights activist.

According to Endin, as Haste left the courthouse on bail, fellow NYPD officers cheered and applauded.

"This man is no hero," he said, "He took the life of an innocent boy."

Outside the courthouse, Patrolman's Benevolence Association President Patrick J. Lynch addressed the crowds of supporters and protesters, saying, "We look forward to a complete review of the facts in this case, which will demonstrate that this police officer believed that he was pursuing an armed felon who bolted rather than be caught with an illegal gun. ... We believe that this officer will be exonerated at trial."

On Wednesday, Graham's neighbors at the house on East 229th Street filed notice of claim to sue the city, according to court documents

The neighbors allege they were traumatized when police, after failing to break down the front door of their house, went to the back door, gained entry, pointed guns at them and their children, and then kicked in the door of Graham's apartment.

In the claim, the neighbors say police had no warrant and lowered their weapons only when informed that surveillance cameras were operating in the house. The cameras did not catch the events in Graham's apartment, but according to the claim, show Graham "casually walking in the front door" as opposed to running as if fleeing from police, as authorities have indicated.

The claim says the tape is now in the custody of the district attorney.

According to Endin, Graham's family has also filed claim to sue the city for wrongful death, pain and suffering, and assault.

"This is a long road, and this is the first step on the road to justice," he said.

According to the District Attorney's Office, Haste is scheduled to return to court on September 13.