Connecticut prosecutors are closing the door on the 45-year-old murder case involving Kennedy cousin Michael Skakel, who was previously accused of bludgeoning to death his 15-year-old neighbor Martha Moxley in Greenwich.

Chief State's Attorney Richard Colangelo Jr. said Friday — exactly 45 years after Moxley's death — that the state will not seek a second trial for Skakel.

During a hearing in Stamford Superior Court, Colangelo filed what is known as a "nolle" — a legal declaration allowing for the case in question to be dismissed after 13 months, his office confirmed to NPR.

The decision comes after Colangelo's review of the case found that of 51 potential prosecution witnesses, 17 have died, making it difficult to prove the case beyond a reasonable doubt, his office said.

This decision effectively ends a case that has garnered wide public attention for decades, due in part to the Skakel family's wealth and the grisly details of the brutal crime.

Skakel was convicted of murder in 2002 and has been free on bail since 2013, when a state judge vacated his conviction.

Moxley was found dead in the wealthy Connecticut suburb of Greenwich in 1975. The case was cold for 25 years until Skakel's arrest in 2000. Skakel was also 15 at the time of the murder.

Skakel, now 60, is a nephew of Robert F. Kennedy's widow Ethel Kennedy.

Copyright 2020 NPR. To see more, visit https://www.npr.org.