One motion sought to have Mehserle's bail lowered from $3 million. The other sought to have the Alameda County District Attorney's Office removed from the case for allegedly conspiring to violate Mehserle's Sixth Amendment right to counsel.
But Los Angeles County Superior Court Judge Ronald Perry denied both motions.
Perry ordered Mehserle, 28, to return to court March 26 to see if there are additional pretrial issues to address and set Mehserle's trial to start June 7.
Mehserle, 28, is charged in connection with the shooting death of Grant, a 22-year-old Hayward man, on the platform of the Fruitvale BART station in Oakland shortly after 2 a.m. on Jan. 1, 2009.
Mehserle, who resigned a week after the incident because he didn't want to cooperate with BART's internal investigation, and other officers were responding to reports that there was a fight on a train. Friends of Grant who were with him at the time have given depositions stating that Grant was one of the people involved in the fight.
Rains has admitted Mehserle shot and killed Grant but claims that the shooting was accidental because Mehserle meant to use his Taser stun gun on Grant but fired his gun by mistake.
In October, Alameda County Superior Court Judge Morris Jacobson ruled that Mehserle's trial should be moved out of the county because the large amount of publicity the case has received jeopardized his chance of getting a fair trial locally.
Jacobson selected Los Angeles County as the new venue and California Supreme Court Chief Justice Ronald George chose Perry to preside over the case.
In his motion seeking to have Mehserle's bail lowered, Rains said legal statutes and the facts of the case "require a substantial reduction in bail."
Mehserle was arrested Jan. 13, 2009, in the Zephyr Cove area of Lake Tahoe in Nevada.
Rains said Mehserle left the Bay Area because his life had been threatened but his attorney at the time, Christopher Miller, was in touch with authorities all along and was prepared to have Mehserle surrender once an arrest warrant was issued.
Rains said Mehserle could have surrendered in Oakland but former Alameda County District Attorney Tom Orloff, who retired last September, insisted on arresting him in Nevada.
The defense lawyer said Mehserle is not a flight risk, has appeared at all court hearings where his presence was required, doesn't have a prior criminal record and doesn't pose a threat to public safety.
Rains said Mehserle, who was born in Germany but moved to the Bay Area at the age of 4, "has always been and continues to be a well-adjusted, mature and well-educated person with strong ethical and personal values and a demonstrated record of acting consistent with the law."
There's a gag order preventing Rains and prosecutor David Stein from speaking to the news media about the case.