Aslam was apprehended from Anand Parbat area yesterday, ACP (Central) Devesh Srivastava said.
He allegedly murdered Rohit Singh along with his friends in Azamgarh on June 5 and fled to Delhi to escape police.
"Despite repeated warnings, Singh remained in touch with his sister. Aslam was enraged at this and conspired with his friends to kill him," Srivastava said.
His arrest came after a member of 'Slum Panchayat', an initiative of central district for community policing, informed police that a suspected person was moving around in the area in suspicious circumstances and was in search of job and shelter.
"He had scratches on his face and the community member further suspected that the person seems to be involved in a quarrel. Aslam was then brought to station yesterday. He tried to misguide police saying that he got scratches on his body while swimming," the ACP said.
But on sustained interrogation, he broke down and confessed to his involvement in the murder, Srivastava said.
