Brothers is charged with five counts of first-degree murder for the deaths of his estranged wife, Joanie Harper; their three children, Marques, Lyndsey and Marshall; and his mother-in-law, Earnestine Harper.
His defense team says he was in Ohio when the family was killed sometime between July 6 and July 8, 2003. The prosecution believes Brothers rented a car and secretly drove from Ohio to California to commit the murders.
If convicted, Brothers could face the death penalty.
The prosecution believes Brothers was an unloving father and husband who carried on several affairs with other women while he was married.
The defense has denied Brothers was ever unfaithful to his wife.
Money motivated Brothers to kill his family because he wanted to unload the burden of his growing family, the prosecution has said.
Brothers had an on-again-off-again relationship with Joanie Harper, according to those close to the couple.
Before his arrest, Brothers worked as a vice principal at Fremont School. He was building a home when the family was killed, friends said.
But Brothers was living in his own apartment while the house was being built and Joanie Harper was living with her mother and children in a separate house.
Brothers was born May 31, 1962, to a poor family in New York and worked his way through college. Brothers became a teacher and was later promoted to school administration.
Brothers has a surviving daughter from a previous relationship with Margaret Kern-Brothers. She is set to graduate from high school this year.
Brothers also had two previous divorces from two other women.
Deputy District Attorney Lisa Green
Green is prosecuting Vincent Brothers.
She has spent the last three years preparing the case and adamantly believes Brothers is guilty. She will pursue the death penalty if Brothers is convicted.
She is one of the top-ranked prosecutors in the Kern County District Attorney's office, where she has worked for more than 20 years.
Until the Brothers case, Green oversaw the homicide department.
During her career, Green carved a niche prosecuting those who attack women and children, and is one of the few prosecutors in the office who has tried a capital murder case.
From going after a woman for poisoning her baby because she allowed it to ingest her drug-tainted breast milk, to prosecuting the first rape case based on DNA evidence in Kern County, Green has long been the champion of women and children.
For as much praise as she receives from victims and the prosecutor's office, however, Green has faced criticism from appeals courts for pushing the legal envelope in court. She testified in a case she was prosecuting, which an appeals court called improper. In another case, she brought up pieces of the defendant's history she should not have, an appeals court ruled.
Green is married to a business attorney and they have three children.
Defense attorney Michael Gardina
Defense attorney Michael Gardina is defending Vincent Brothers.
Gardina believes Brothers was in Ohio at the time of the killing and could not have driven back as the prosecution has argued.
He took over the case for Kevin Little, who bowed out after demanding more time to prepare than the judge was willing to give.
Gardina too has asked for many delays. He received most of them. But his last request was denied.
In one of his more high-profile cases, Gardina defended Juan Villa Ramirez, who was convicted and sentenced to death in 2001 for killing 17-year-old Arvin High School football star Chad Yarbrough.
He has had some successes.
He was able to get client Jose Segovia Onsurez, who was accused of murdering three siblings, released from jail in 2003 by arguing that his right to a speedy trial was violated.
Gardina started out in Los Angeles, and later opened a private practice in Bakersfield.
Gardina has a son and daughter.
In his spare time he writes screenplays and plays the guitar.
Defense attorney Anthony Bryan
Bryan is Vincent Brothers' secondary attorney.
Bryan frequently clashes with Green and Kern County Superior Court Judge Michael Bush, who is presiding over the trial.
He has decades of experience defending people who face the death penalty, including in Los Angeles and Bakersfield.
He also worked with Gardina on the Juan Villa Ramirez case.
Bryan won the Atticus Finch Award in 2003 given by Kern County defense attorneys.
His son, Christopher, is also an attorney.
In his spare time, Bryan writes poetry, which he doesn't share with anyone, and reads extensively.
He is an avid supporter of the NRA.
He also supports independence for Northern Ireland.
Harper, 70, was found July 8, 2003, shot to death in the hallway of her home at P and Third streets.
Harper was a longtime crusader for defendants' rights in Bakersfield. She became particularly prominent when she took up the cause of Offord Rollins IV, a man accused of killing his sometimes girlfriend, Marta Madera Rodriguez, in 1991.
After a jury could not reach a verdict on the Rollins case, the prosecution decided not to seek a second trial. Harper felt the Sheriff's Department focused on just one suspect when investigators should have been pursuing other possible leads.
She lived with her daughter Joanie Harper and her three children.
Those close to the Harpers said she had difficulties with Vincent Brothers when he lived in her house.
But before the family was killed, Brothers was building a house for his wife and children with a room for Earnestine.
Those close to Earnestine remember her as a deeply religious woman.
She has four surviving children.
The former Bakersfield High School basketball star had a rocky relationship with Vincent Brothers. They married in January 2000. Her marriage to Brothers was annulled in September 2001.
The couple remarried in January 2003, but Brothers moved out of the house in April 2003.
They had three children together.
Those close to Joanie Harper said her marriage to Brothers was strange. They rarely spent time together in public and he seemed cold, friends said.
The prosecution believes that Brothers had affairs during the marriage -- an allegation the defense denies.
Harper had worked as a campus supervisor for the Bakersfield City School District since 1994. She was responsible for campus security and safety but she also worked with the students and community groups.
Harper was close friends with a woman named Kelsey Spann. Rumors swirled that the two were having an affair, but family and friends from both sides, including Brothers himself, say that was not true.
On the likely day of her death, Joanie Harper went to church with her family to show off her newest baby. While there, she confessed "she had sin and that she was going to put a close to that part of her life."
The pastor of the church said she was talking about her relationship with Brothers.
The children: Marques Juwan, Lyndsey Michelle and Marshall Harper
Marques was 4 years old, Lyndsey was 2 and Marshall was 6 weeks old when they were found shot to death in bed with their mother, Joanie. Marques had just graduated from the McKinley preschool program on June 4, 2003. Marshall made his first appearance in church on July 6, 2003, the day prosecutors believe the family was killed.
Kern County Superior Court Judge Michael Bush
Kern County Superior Court Judge Michael Bush will preside over Brothers' trial. He is known as a fair judge with a pleasant courtroom demeanor.
The defense asked Bush to remove himself from the case because Deputy District Attorney Lisa Green, who is prosecuting the Brothers case, helped with Bush's 1996 election to the bench. Bush denied this request because he does not now socialize with Green and believes he can be fair to both sides.
Bush worked for the Kern County District Attorney's office from 1985 to 1996.
He has presided over many criminal cases including a death penalty case.
In 2004, he sentenced Larry Kusuth Hazlett Jr. to death for the 1978 killing of Rosamond beauty queen Tana Woolley.
Bush also has experience in juvenile court. While there, he started a truancy court to ensure children and possibly their parents would be punished for chronic truancy.
When he left juvenile court, some of his biggest supporters were upset and wanted him to return.
Bush is also active outside of court. He is a member of the Kiwanis Club and is involved with the Boy Scouts.