Damien Lockhart, a former Framingham man, is seeking parole for the fifth time nearly 30 years after he murdered Kimberly Bolton, a 17-year-old girl. The family of Bolton, who was murdered in 1996, is urging the public to write letters to the state Parole Board in Natick, asking it to keep Lockhart behind bars. Lockhart last sought parole a year ago, but his request was unsuccessful due to a deadlocked 3-3 vote among the six members. The parole board credited Lockhart for working to improve himself while incarcerated. However, Bolton's aunt, Carol Aitken-Young, believes Lockhart should remain in prison for life.