The second murder trial of Karen Read, whose case has sparked a national debate on police accountability and won her legions of devoted fans, will begin Tuesday with both sides laying out conflicting theories of how her Boston police officer boyfriend ended up dead.

The second murder trial of Karen Read, who is accused of causing the death of her Boston police officer boyfriend, entered Day 2 as witness testimony resumed Wednesday.

Karen Read arrived at court to a group of supporters ahead of her second murder trial, where she stands accused of killing her police officer boyfriend with her vehicle. Read, 45, looked stylish in a black double-breasted dress and wore her hair long and flowing as she approached the Norfolk County Courthouse in Dedham,