FORT COLLINS, Colo. -- Was it a case of fatal attraction, or do investigators have the wrong person?

Heather Garraus was gunned down in the Colorado State Employees Credit Union parking lot in Greeley one year ago.

On Friday, prosecutors put the victim's husband on the stand.

Ignacio Garraus testified that he'd carried on a near three year affair with the defendant and that she gave birth to his son.

Under cross examination Garraus said Shawna Nelson became pregnant twice during their affair, once in 2004, and again in 2005. He said the first pregnancy was terminated by an abortion, which he paid for.

The second pregnancy ended in the birth of a son, Christian.

During redirect, Garraus said Nelson told him she was on birth control. "She got pregnant twice while on birth control," the former Greeley police officer stated.

Garraus said his wife had heard rumors that Nelson's baby was his, but he denied it until she caught him at a bar with Nelson and one of her friends.

He said he confessed everything, the affair, the pregnancy, the birth.

Heather Garraus demanded that he end the affair. He says he did, but that when he told Nelson it was over, Nelson wasn't happy.

Soon Garraus received several text messages. One of them included a picture of Shawna's infant son, with a message underneath saying, "Ig's flesh and blood."

Garraus said the picture was forwarded to his wife's phone.

Another ominous text message said, "My loyalty is gone. I loved u and u f***** me. Be prepared."

He said both messages were sent from Nelson's phone.

The victim's daughter also testified. She told the court that her mom took her to school the morning of Jan. 23, 2007, and that her dad picked her up.

Victoria Garraus, now in fifth grade, said they went to get some ice cream, then went shopping, then went home.

She said while she was doing homework, the phone rang. It was her mom's best friend asking for Ignacio.

He picked up the phone and was told to get down to the credit union right away.

Victoria started to cry as she told the court that she didn't find out her mom had been shot until she and father got to the credit union.

Garraus testified that from there they went to the hospital.

"Peter Maxwell blocked my entrance into the trauma room," Garraus said. "He told me Heather was dead."

Garraus said he then went to tell his daughter the news.

"Victoria was outside by the patrol car. As soon as I found out I left the trauma room, grabbed Victoria out of the car and went to the end of the ER where I said, 'Victoria, Mommy's dead.'"

When questioned by the public defender, Garraus admitted that he lied to his wife several times to cover up the affair.

He admitted that his father knew about the affair and about Christian before Heather did.

Prosecutors also put Kell Hulsey on the stand. He's an officer with the Greeley Police Department, assigned to the Weld County Drug Task Force.

Hulsey was working with Nelson's husband, Ken, the night of the shooting.

They heard the call go out on the radio, with Nelson's name mentioned as a suspect.

Hulsey testified that Ken Nelson wanted to go see what happened right away. Hulsey said, "Hold on," stalling for time to call the sergeant, then went outside and got into the passenger side door of Ken Nelson's vehicle.

When asked if Ken Nelson had a gun, Hulsey replied, "Yes." He said Ken Nelson gave him the gun and said, "Take this."

Hulsey said that on the drive over to the west side of town, Ken Nelson tried to call someone on his cell phone, but slammed it shut and said, "She's not home." He assumed Ken Nelson was talking about Shawna Nelson.

They spotted Ken Nelson's pickup at 18th Street and 65th Avenue.

"As we were crossing 65th, Ken yelled, 'Give me my f***** gun.'" But, Hulsey said he didn't give it to him. He kept it under the seat where he was sitting.

He said Ken Nelson slammed on the brakes and got out of the Cherokee. The pickup was right next to them.

The suspect was sitting inside.

"Ken was yelling 'What did you do, what did you do, where are my kids, where are my kids?'" Hulsey said.

Hulsey said he jumped between Ken and Shawna Nelson because he thought Ken Nelson was going to hit her.

When asked if the defendant told him what she was doing, he said she told him she'd gone to the liquor store.

He added that Shawna Nelson got upset when she learned about the shooting and realized she was a suspect.