A mistrial is declared in the murder trial of a man accused of shooting and killing a Miami Police Detective.

Andrew Rolle is accused of gunning down James Walker in 2008.

His defense team claims there was a discovery violation by the state in connection to a jailhouse snitch who was about to testify.

Rolle is claiming self-defense in this case.

Cops say Andrew Rolle shot Det. James Walker as Walker sat in his unmarked police cruiser in North Miami Beach. The officer was visiting his estranged wife.

Rolle apparently mistook the cruiser as his getaway car.