Bronwyn Ingram, once described by Filner as "San Diego's first lady," said she broke up with Filner after noticing "behavorial changes in Bob that rendered him, in my opinion, less than optimally effective as mayor."
But since resigning, she wrote, he "has taken the responsibility of healing himself as seriously and with as much determination as he displayed throughout his life."
Ingram mentioned Filner's experience as a Freedom Rider during the civil rights movement in the South.
Filner's two ex-wives and his son also supplied letters to be considered by Judge Robert Trentacosta. Letters of support were also written by a Baptist minister and a San Diego lawyer now married to one of Filner's ex-wives.
Trentacosta on Monday accepted the major terms of the plea bargain, sentencing him to 90 days of home confinement with no jail time.
Filner pleaded guilty in October to a felony charge of false imprisonment and two of misdemeanor battery, all involving women. He had resigned Aug. 30 amid accusations from nearly two dozen women of sexual misbehavior.
Under terms of the plea bargain, Trentacosta ordered Filner to serve 90 days of home confinement starting Jan. 1. He also reduced his city pension and fined Filner approximately $1,500.
The judge placed Filner on probation for three years. If he violates probation, he faces jail, the judge ruled, adding that Filner cannot seek office during his probation.
While on probation, he will wear a GPS monitor so police will know if he leaves his home for anything except for medical appointments, religious services or court appointments.
The probation report said that Filner is undergoing counseling and is taking medication commonly prescribed for depression, anxiety and mood disorders.
While in Congress, he was seeing a psychiatrist and had prescriptions to stabilize his moods but once returning to San Diego to run for mayor, he stopped taking the medications, according to the report.
Filner's attorney, Jerry Coughlan, told reporters after the sentencing that there is a "medication issue" to help explain Filner's behavior in his months as mayor.
None of the three victims, listed only as Jane Does 1, 2 and 3, opted to make a "victim's impact statement." If the victims request restitution for damages, a hearing will be held, Trentacosta said.
In a brief statement, Filner offered an apology to his family, staff, supporters and to "the women I have hurt and offended."
The 71-year-old Democrat said his misbehavior toward women "will never be repeated." He said he will work to regain the public's trust.
"I look forward to making further contributions to the city I love," Filner said.
The prosecutor, Deputy Atty. Gen. Melissa Mandel, told Trentacosta that Filner's actions offended and demeaned the three victims and hurt San Diego. She said some of the victims had come to meet Filner to discuss public issues and instead were treated disrespectfully.
Filner used "the power of public office" to demean and scare women. "Filner sold himself to voters as a champion of civil rights" but his actions showed him to be different, Mandel said.
In the felony case, Filner grabbed a woman in a headlock. In the misdemeanor cases, Filner kissed one woman and grabbed another on the buttocks.