The longtime girlfriend of gangster James "Whitey" Bulger has been sentenced to an additional 21 months in prison for refusing to testify before a grand jury investigating whether other people helped Bulger while he was a fugitive.

Catherine Greig already is serving an eight-year prison term for helping Bulger evade capture during the couple's 16 years on the run together. They were captured in Santa Monica, California, in 2011.

On Thursday, federal prosecutors asked the judge to add a little over three years to her prison time for her conviction on a criminal contempt charge. Greig's lawyer asked for leniency and said she should not get any more than six months.

The 86-year-old Bulger is serving a life sentence after being convicted in 2013 for his role in 11 murders.