The arrested person was identified as Rakesh Bijliwala, an ex-employee of the contractor of a private distribution company, police said.
Acting on a tip-off, the Crime Branch arrested Rakesh, a resident of Uttam Nagar, near Nawada Metro Station.
On March 6, one Mohit was allegedly stabbed to death by Rakesh and his associates after an argument broke out between them.
"Police received information that Rakesh would on March 8 come near Nawada Metro Station. Acting on the tip-off, police laid a trap and arrested him," an official said.
"After sometime, Rakesh along with his friends came back to Rahul and Mohit, attacked them with knives and fled from the spot.
"Mohit was stabbed to death while Rahul suffered serious injuries," he said, adding that the other accused would be arrested soon.