The four accused have been identified as Mohit, Intazar, Deen Mohd and Irshad of Baghpat district, said SSP HN Singh.
Sanjiv Malik, former General Secretary of Budhana Bar Association was shot dead on Monday by six accused over an old enmity, following which four of them were lynched by an irate mob.
A case has been registered against six persons including the four deceased in connection with the lawyer's murder. Two others are unidentified yet, Singh said.