The driver involved in the accident in which Tempe bicyclist and environmental activist Jay Fretz was killed has pleaded guilty to speeding in the incident.

A Tempe police report says Rebecca Singer of Tempe was issued a civil traffic violation for "failure to operate at a speed to exercise reasonable care for others." Police said alcohol or drugs were not a factor in the accident.

Fretz, 36, was riding his bike home from work on May 17 when he was struck by a car at the intersection of McClintock and Alameda drives. He died later that evening, leaving behind a 5-year-old daughter and a wife battling breast cancer. It was their seventh wedding anniversary.

The Fretz family has filed a civil suit against Singer and declined to comment due to those legal proceedings.

Brendan O'Connell, Singer's attorney, declined to comment as well.

In the police report, Singer said she had a green light as she headed north on McClintock and collided with Fretz.

One of the witnesses, David Gomez, who was riding his bike about 50-100 feet in front of Fretz, said he and Fretz had a green light as they crossed McClintock on Alameda. Soon after Gomez cleared the intersection, he said he heard a crash and the sound of a vehicle skidding behind him and turned to see what happened.

"I immediately noted that the light was still green for our direction of travel," Gomez recalled.

The police report said a second witness didn't notice whether the light was green or red at the time of the accident but noted that cars were stopped in the southbound lanes of McClintock. A third witness said the light was red going southbound on McClintock, and a fourth witness said it was yellow and phased to red going southbound on McClintock when the collision occurred.

After studying the pertinent traffic signals and their timing, re-enacting multiple scenarios, and comparing witness accounts, investigators concluded there was no way to determine who had the green or red traffic signal at the intersection at the time of the collision.

Sgt. Steve Carbajal of the Tempe Police Department said that because no determination could be made regarding who ran the red light, the matter remains a civil traffic issue rather than a more serious criminal case.

Singer said she was traveling about 40 mph at the time of the accident. The speed limit in that intersection is 35 mph, part of a reduced-speed zone adjacent to McClintock High School. Investigators didn't specify the estimated speed Singer was traveling in the report, but one formula suggested it was a minimum of 32 mph when she began to skid.