FORT COLLINS, Colo. -- "I don't know what to say." Those were the words that jurors heard murder suspect Shawna Nelson utter several times during a videotaped police interview that prosecutors played Monday.

The interview was recorded the night Heather Garraus was shot and killed outside the credit union where she worked.

Detective Greg Tharp conducted the interview at the old police headquarters in Greeley.

During the interview, Nelson told Tharp that she'd used her husband's pickup to get some liquor because it was icy out and she didn't want her Expedition to slide into his F-250 which was parked in the driveway behind her sport utility vehicle in the garage.

She also told Tharp that once she got to the liquor store she didn't bother getting out of the pickup because she realized she'd left her purse at home. She said she was driving back home when she was stopped by her husband, Ken, and by fellow Drug Task Force officer Kell Hulsey.

When Tharp asked if she knew who the shooting victim was, she responded, "I can't remember if Kell told me. I don't know."

When Tharp told her it was Heather, there was a six second pause on the tape, then an audible sigh.

She did not ask if Heather survived.

Tharp told Nelson that witnesses placed her at the scene. She asked him, "How? I don't know."

Later she said, "I don't know what to say."

"I guess if I'm the suspect, I don't know, I guess you better get me an attorney. I don't know what else to do. I don't know Greg."

After the interview, Nelson stood and hugged the interrogator.

Witnesses also talked about other key pieces of evidence.

They never recovered the murder weapon, but they did recover a gun box for a Glock 22, which Tharp said is a .40-caliber semi-automatic handgun.

The box, found in the Nelson's basement, was empty, but did contain paperwork indicating that the weapon was purchased from Garretson's Sporting Goods in Greeley on July 11, 2006, by the suspect's husband.

Police said that Glock has not been accounted for.

Authorities also recovered two shoes, which they believe were tossed from the suspect's vehicle as she made her way home.

The left shoe was found on a snow bank along 65th Avenue just north of 20th Street, and the right shoe was found on 65th Avenue, a little further north.

Tharp said that when the suspect was pulled over by her own husband and a fellow drug task force officer on the night of the shooting, she wasn't wearing any shoes, just socks.

When asked what the weather was like, Tharp answered, "It was extremely cold." He noted that there was ice and snow on the ground, and that temperatures were dropping close to the single digits.

In opening statements last Thursday, prosecutors told jurors that the suspect's DNA was found inside the shoes which were recovered a short distance from where the suspect had been pulled over.

The suspect's husband, Ken Nelson, is expected to testify Tuesday or Wednesday. He is charged with tampering with evidence in the case and there are allegations he disposed of the missing Glock handgun before his wife's arrest.