PORTLAND, Ore. -- DeDe Spicher and Terri Moulton-Horman were both unaccounted for during the same period of time the day Kyron Horman disappeared, based on information revealed by investigators and on information from KGW sources.

Sources tell KGW that DeDe Spicher, a close friend of Terri's, was doing gardening work not far from the Horman family home on the day Kyron disappeared, but was unaccounted for during a three-hour period from 10 a.m. to 1 p.m. She could not be reached by cell phone during this time either, according to sources.

Sources also tell KGW that, during the period of time DeDe was unaccounted for, her car remained at the property where she had been gardening. According to sources, that detail is significant because, if DeDe left the property as investigators believe, she would have had to leave in another vehicle.

Meanwhile, at a Wednesday press conference, investigators focused on the movements of the Horman family pickup truck on the day Kyron disappeared. Investigators specifically asked for any witnesses who might have seen the pickup in that same area of Skyline between 10:15 and 11:30 a.m. Sources tell KGW that investigators identified that as the time between when Terri left a Beaverton Fred Meyer and her next known stop, at her personal gym. More: Truck sighting locations

These timelines leave a one-hour, fifteen-minute block of time in the middle of the day Kyron disappeared where the whereabouts of both Terri and DeDe was still under investigation. At Wednesday's press conference, deputies focused in on specific roads in the Skyline area where the family's white truck may have been during that window of time.

According to a former police detective, that's a significant investigative detail.

I think you take map and you say 'how long would it take if you had an hour and a half to go here?' said C.W. Jensen, a former Portland Police homicide detective. If you had an hour and a half how long would it take to go here, here, here? And you know, ultimately--how far could you go in an hour and a half in this time frame? And what they're telling us is she was here..she was here...we know she was here...and they're asking us now...could you help us out.

Home where Spicher gardened searched

Investigators spent Sunday searching the home where Spicher gardened the morning of June 4.

The person who owns the house where Spicher gardened, who is cooperating with investigators, told investigators she called Spicher on her cell phone but she didn't answer, the source told KGW. A person who was working with Spicher,who is also cooperating with investigators, told them of trying to unsuccessfully find Spicher. Both people have told investigators they have no idea where Spicher was during that period of time.

More: Who is DeDe Spicher?

Sources tell KGW that police have also searched Spicher's home.

Spicher has known Terri and Kaine for about seven years.

Complete coverage: Search for Kyron Horman