Rahul, in his 20s, owned a toilet complex in Punjabi Market and was a resident of Mundka.
When he arrived there, he found three to four men taking drugs. He also came to know that his mother had been thrashed by them, they added.
He asked them to leave. The men left but later returned to avenge the insult. They stabbed Rahul multiple times and when his mother tried to intervene, they thrashed her again, police said.
An e-rickshaw driver was beaten to death by nearly a dozen men on May 27, after he had objected to two men urinating in public outside GTB Nagar Metro station in northwest Delhi. Two persons were arrested in connection with that case.