Friends and relatives held a prayer vigil over the weekend for pro-life activist James Pouillon on the site where he was shot to death last Friday.
Pouillon was a familiar figure in the pro-life movement in Owosso, Michigan.
Police believe the suspect, Harlan Drake, shot Pouillon to death in front of the high school where he was protesting because he was disturbed by the graphic pictures of aborted babies that Pouillon used in his protests.
"Mr. Drake did not believe that children should view the graphic material that was on the signs that Mr. Pouillon carried," an official said.
Friends say Pouillon was a non-violent man whose mission was simply to fight for the lives of the unborn.
More than 200 supporters held a vigil to remember Pouillon and his cause.
"We really don't want any violence, but we've got to get it across to the people that we are killing a baby, a baby who cannot speak for himself," one woman said. "And as the Bible says, that we are to be the ones who speak for those who cannot speak for themselves."
"I'm proof that the pro-life cause helps people," another said. "I got pregnant at 19... and I thought of having an abortion. It was the pro-lifers that gave me hope, and the courage to face my parents."
President Obama issued a statement over the weekend, calling Pouillon's murder "deplorable." Still, pro-life activists in Washington want the Justice Department to do more.
They want the government to give Pouillon's murder the same rigorous investigation and treatment it gave to the murder of abortion doctor George Tiller, who was shot to death in his church in June.
"An American citizen has been gunned down on 9/11 for exercising their First Amendment speech," said Patrick Mahoney of the Christian Defense Coalition. "Please make the same commitment that you did when George Tiller was killed."
When Tiller was killed, advocates on both sides of the abortion divide were quick to issue statements condemning the shooting.
So far, however, no major pro-choice group has publicly condemned Pouillon's murder.