Relatives of murder victims whose cases were never resolved launched a group Saturday that will attempt to abolish the statute of limitations for homicides.

Among the 20 members of the group are William Hawker, the father of slain British Nova teacher Lindsay Hawker. The chairman is Yoshiyuki Miyazawa, 80, whose son, daughter-in-law and two grandchildren were killed in 2000.

"As the group makes its first step, I am expecting a lot . . . These activities are not only for ourselves, but for the future — so that this kind of situation will not continue," Miyazawa told a press conference in Tokyo.

To pressure the state, the group, Sora no Kai, hopes to submit petitions to the Justice Ministry and collect signatures from people who support its goal. It also plans to cooperate with other crime victim organizations, a member said.

The statute of limitations for capital crimes, such as murder, was extended to 25 years from 15 years in 2005 under a revision of the Code of Criminal Procedure, but the group is questioning the system itself.

The Justice Ministry is considering extending or possibly abolishing the limits on serious crimes from January amid growing calls for a review of the system.

William Hawker, whose daughter was killed in Chiba Prefecture in 2007, was absent from Saturday's meeting but sent a message in which he also questioned the limitations system, the group said.

Limitations periods are an idea Japan adopted from France.