More than eight months after a head-on collision on Route 38 claimed the life of one man and seriously injured another, the office of District Attorney Gerry Leone has concluded its investigation.

According to a spokesman for the DA's office, the accident that killed Stephen Allder, 41, of Medford, was caused with Allder's vehicle crossed over the yellow line and into the path of an oncoming car.

The accident took place on April 11 at around 7:30 a.m., on a curve in the road near Mahoney's Garden Center.

The DA's investigation did not draw a conclusion as to what caused Allder's car to drift over the center line.

Members of Allder's family have expressed frustration in recent weeks that they have been unable to get a complete copy of the DA's report. In emails to Tewklsbury Patch, they have indicated they believe the second driver in the case was operating a motor vehicle with a suspended license.

The spokesman for the DA's office did not comment on the Allder family claims, except to say that no citations were issued and no criminal charges would be filed against the second driver. The identity of the second driver has not been released.