ST. LOUIS COUNTY • A tearful Jacob Runge told jurors that the image of his mother crying kept him from pulling the trigger the day that he made a suicide pact with his best friend.

Runge, who took the witness stand in his defense Wednesday, testified he wasn't really sure that his friend Alex Harkins, 21, would kill himself either.

"I thought we might be home laughing about it later that night," Runge said.

But Harkins didn't back out when the two men went to the St. Stanislaus Conservation Area in Hazelwood last year with a plan and a gun.

Now a St. Louis County jury must decide if Runge committed a crime that night. Runge, 22, is charged with voluntary manslaughter and armed criminal action. The prosecutor, David Pisarkiewicz, said he "knowingly assisted" Harkins in his death by providing the gun and driving him to the conservation area on May 29, 2009. If convicted, he faces up to life in prison. The case went to the jury Wednesday and deliberations will resume today.

On the stand, Runge said he didn't tell Harkins that he had second thoughts.

"In his mind, it was too late to back out," Runge said. "He told me the worst insult I could do is to not go through with it."

Runge said he had talked Harkins out of suicide in the past. Still, Harkins had tried to kill himself several times and brought up the subject often, he said.

Runge told jurors he thought a last-minute act of kindness might keep Harkins from pulling the trigger this time.

Runge said he shouted "I love you, man" just before Harkins died.

"I figured if I told him that, he wouldn't do it," Runge said. "What other reason is there to live than love? I thought that it would jog his memory of all these other people who love him, too."

But it didn't work.

After watching Harkins fall, Runge said he picked up the gun to complete the pact. But there were no more bullets in the 9mm. Runge, who had loaded the gun at the park, said he meant to put three in the magazine but got distracted by mosquitoes.

So he said he tried to load with another bullet but his fingers wouldn't cooperate. He shouted and then began running. He decided he could die the next day.

Runge said he went home to the apartment he shared with his mother in St. Peters and thought about suicide for the next several days. He picked up the handgun several times again, but didn't come close to firing until Harkins' parents knocked on his door.

He didn't want to face them, he said. He wanted to die instead.

"I didn't know what to say," Runge recalled during his testimony. "I knew they wanted some peace. So I took them to where their son had killed himself."

Runge, who has been out of jail on bond, said he struggles with depression and has been getting counseling since Harkins' death.

His attorney, Susan Roach, asked if he still thinks about killing himself.

"I don't think those thoughts will ever go away," Runge said.