Slain Barnard College student Tessa Majors had gone to the Manhattan park where she was stabbed to death to buy marijuana, a friend has told investigators.

Majors, 18, was in Morningside Park near her school at around 7pm Wednesday, when she was fatally stabbed by a group of teenagers in a suspected botched robbery, the head of the NYPD sergeant's union says.

'What I am understanding is that [Majors] was in the park to buy marijuana,' Sergeants Benevolent Association president Ed Mullins said during an interview on AM 970 show, the New York Post reports.

Tesa Majors, 18, who died after she was attacked about 7 p.m. Wednesday, had gone to a Manhattan park near her school to purchase pot when she was fatally stabbed by a group of teenagers in a botched robbery, the head of the NYPD sergeant's union says

NYPD sources confirmed that they are looking into the angle that Majors (pictured) was in the park to purchase marijuana, a tip that came from one of Majors' college friends

Majors crawled up a steep flight of steps in the park desperately seeking help after she was stabbed. A security guard at the top of the steps called 911 when he spotted her, but she died in a nearby hospital

NYPD sources confirmed to the Post that they are looking into the angle, which came from one of Majors' college friends.

Neighbors of the charged teen say that he was known to hang around smoking marijuana, the Post reports.

Meanwhile, workers at a nearby deli say the suspects were told by investigators the suspects were some of the same youths who had chased another young girl into the business five days earlier.

'We know these kids from a school close by,' one of the workers told DailyMail.com on Sunday.

'We feel so bad for the girl, she is so young', the employee said referring Majors. He declined to give his name.

The young girl who was chased into the store was followed in by the 13-year-old boy, who then kicked her to the floor, an employee told The Daily Beast. She claims she took the boy's picture and called police.

Investigators who later returned to the business after Majors was slain, said the suspects in her murder were the 'same kids' as those believed to have chased down the young, unidentified girl.

Police have charged a 13-year-old suspect in Majors' death, and have also detained a 14-year-old male suspect, who was released while cops bolster their case. A third youth is still wanted in connection with the murder.

Majors battled in vain to fight off the muggers in the attack, biting one assailant on the hand, it was revealed during a court hearing following the murder this week.

The 13-year-old male suspect who appeared in court on Friday claimed he just watched as his two friends, who are similar in age, carried out the murder during the trio's botched mugging, according to police.

At Friday's hearing, the court ordered the 13-year-old held without bail.

The name of the boy, a Harlem resident, is being withheld because he will be tried as a juvenile delinquent in family court.

At the hearing, Detective Vincent Signoretti laid out the preliminary findings of the investigation, telling how the suspect had confessed to deciding to do a mugging with two middle school friends after classes let out on Wednesday.

The trio made their way to Morningside Park, situated on a steep slope that separates the wealthy sister campuses of Barnard and Columbia University from Harlem below.

'They followed a man with the intention of robbing him and decided not to,' Signoretti said, according to the New York Times.

Later, the trio spotted Majors and decided to victimize her, according to the boy's confession.

The boy told police that he watched his two friends grab the student, put her into a chokehold and remove items from her pockets, the officer testified.

The boy said that his friend dropped a knife as he held Majors in the chokehold, and that he picked it up and handed it to the friend, who then stabbed the college student, the court heard.

The trio removed her wallet and fled, according to the confession, as Majors crawled up a steep flight of steps in the park desperately seeking help.

The entrance to Barnard College, where Majors was a student before she was stabbed to death on Wednesday

Tributes were left at the school in Majors' memory following her murder on Wednesday

A security guard at the top of the steps called 911 when he spotted her, but she died in a nearby hospital.

The boy said that after the attack, one of his friends told him that Majors had bit his fingers as he tried to subdue her in a choke-hold.

A folding knife with a four-inch blade, which is being tested for DNA and fingerprints, was found near the scene of the attack, a law enforcement source told the Times.

The case broke when police detained the 13-year-old on suspicion of trespassing in a building near the park on Thursday. He was questioned in the presence of guardians and made incriminating statement tying himself to the murder, according to police.

The 13-year-old boy has not yet been formally arraigned, but faces charges of second-degree felony murder, robbery and criminal possession of a weapon.

He is due back in court on Tuesday.

In the meantime, workers at the 118 Deli, a block north of the park, said they have had interactions with the suspects.

In the meantime, workers at the 118 Deli, a block north of the park, said they have had interactions with the suspects. The deli is pictured above

The woman behind the counter, who declined to give her name, said a younger girl lost her footing coming into the store about five days earlier. She was followed in by a 13-year-old boy, the woman said.

'He kicked her on the floor,' the woman behind the counter would recall, the Daily Beast reports. 'Situation like that, all I know is I got to call the cops. Once I see something like that, I'm calling the cops.'

The woman also took a cell phone image of the boy through the deli window when he rejoined four teens outside on Manhattan Avenue. Two were males, and two females.

The boy who kicked the girl was described as wearing a black parka with red and white stripes. He had the hood up. The boy and his friends were gone when cops showed up.

The girl who was kicked to the floor remained in the store. The woman behind the counter claimed she was told that she and the boy who kicked her down were going together.

'I told her to speak with the cops,' the woman says. She and the other workers at the store complained the same youths were responsible for stealing cakes from the deli an threatening a 67-year-old manager.

The campus security booth at the top of the steps where Majors went looking for help

'Don't steal,' the manager was said to have told the youths, who responded by challenging to come from behind the counter and confront them, reports the Daily Beast.

'They start talking bad; 'Come over and I will show you,' Rachid Ousaji recalled on Friday.

The teens were also alleged to have struck a man working behind the counter with a snowball.

'They robbing the store, I told them to stop,' the man told the Daily Beast.

Cops were called bout the youth several times.

'I call, I call, I call', one of the workers said. 'Sometimes, I'm shamed to always call 911'.

Deli workers said the youths were overheard speaking of robberies they committed. The woman behind the counter said they even mentioned robbing someone in Morningside Park, where Majors was stabbed to death.

'The first thing that came to mind was those kids,' the woman behind the counter recalled, when she had heard Majors was fatally attacked.

She said she wasn't surprised when cops came calling afterwards. A detective said they were looking for a group of teenagers and wanted to watch the deli's surveillance video recordings.

After the 13-year-old suspect's arraignment, the woman behind the counter made the comment that 'This time they got themselves into something'.

'Somebody died'.