A 55-year-old lawyer who called up Rashtriya Janata Dal (RJD) chief Laloo Prasad Yadav and started screaming obscenities and issuing threats against him was arrested and sent to jail in Darbhanga district of Bihar.Maheshwar Prasad Shahi called up on Yadav’s personal number hoping to air his grievances to the RJD chief. He got a staffer instead who started questioning him. Shahi at that point started abusing the RJD chief. ‘‘The staffer asked him who he was but he just used obscenities and he hung up. There was caller ID on that phone and they traced the number back to a STD booth owner in Darbhanga. The staffer called up the number and was told that it belonged to a STD booth,’’ said Darbhanga SP Sunil Kumar.He notified the RJD chief and all the top police officials in Darbhanga were immediately notified about the crank call. The police swung into action immediately and with the help of the booth owner Chati Prasad who told the police that it was Shahi who had made a call at 4.30 pm on Monday.The boothowner told the police that Shahi had threatened him as well. Shahi was put under preventive arrest and was produced in a SDO court in Darbhanga on Tuesday. In November last year 50-year-old RJD worker Arvind Kumar from Bhojpur district had been arrested after he entered the Laloo Yadav’s bedroom in the middle of the night.