COLORADO SPRINGS, COLO. (CNA/EWTN News) - After Friday's shooting at a Colorado Planned Parenthood clinic killed three but with an official motive for the act not determined, pro-life groups have condemned any act of violence against abortion clinics.

"We condemn violence of any kind against Planned Parenthood, abortionists, or any abortion industry workers," said Kristan Hawkins, president of Students for Life, in a statement issued hours after the Nov. 27 shootings. "People using violence to promote their views should be held criminally liable for their actions. Period. We pray for the victims and their families of this senseless act."

The pro-life advocacy group Susan B. Anthony List also offered prayers for the shooting victims and their families. "Violence is never justified. The actions of the shooter are in complete contradiction to the aims of the pro-life movement," stated Marjorie Dannenfelser, president of Susan B. Anthony List, on Monday.

They also praised police officer Garrett Swasey, who was killed in the line of duty responding to the shooting.

"Officer Garrett Swasey embodies the spirit of the pro-life movement in this tragedy," Dannelfelser said, adding that he "charged headfirst into danger to protect lives inside their [Planned Parenthood's] clinic. He believed, as we do, that all lives are equally valuable and worthy of protection."

The alleged shooter, 57 year-old Robert Lewis Dear, killed three and injured nine at the Colorado Springs Planned Parenthood clinic, and surrendered himself to police after a five-hour standoff. He injured five police officers who responded to the shooting, and killed one. Dear is from North Carolina but lived in an RV in Hartsel, 65 miles west of Colorado Springs.

According to law enforcement sources, he allegedly said "no more baby parts" while in police custody as just one of many remarks, NBC reported. Officials have not confirmed Dear's motive for the shooting.

That alleged phrase may have been made in reference to a series of videos released by a citizen journalist group Center for Medical Progress detailing Planned Parenthood's role in offering fetal body parts of babies aborted at their clinics to tissue harvesters for compensation.

Planned Parenthood's advocacy arm has already circulated a petition connecting the shooting to larger "opposition to Planned Parenthood and access to abortion," adding that "acts of domestic terrorism do not exist in a vacuum."

Their petition was addressed to "those who go to unimaginable extremes to close our doors."

"We fight your legislation to limit reproductive rights and health care in every corner of our country," the petition stated. "We believe your actions and words hurt women — whether by making it impossible to seek health care or by creating a climate of disrespect and hostility that fosters extremist violence."

The Center for Medical Progress responded to the shooting with a Dec. 28 statement condemning the "barbaric" act "by a violent madman."

"We applaud the heroic efforts of law enforcement to stop the violence quickly and rescue the victims, and our thoughts and prayers are with the wounded, the lost, and their families," the statement added.

Ultimately, "it's just a little unclear" what, if anything, is behind the shooting, said Jon A. Shields, professor of government at Claremont McKenna College, in an interview with CNA. Shields' areas of expertise include abortion and American culture & politics.

Police have not established an official motive, he insisted, and from the current information Dear's shooting appears more like other mass shootings perpetrated by a mentally ill lone-wolf gunman than a religiously-motivated act of violence against an abortion clinic.

Dear's history, which includes arrests for domestic violence and being a "peeping tom," testimony from a neighbor to the AP that he was incoherent in his conversations, and an alleged interest in BDSM, would not fit with the typical profile of an anti-abortion radical attacking an abortion clinic, Shields added.

"The police officers, as far as I can tell, haven't established a motive," he said. "Precisely because [Dear's] conversations with them seemed utterly incoherent. So I think that too suggests that he's a schizophrenic or he's truly disturbed and crazy."

In contrast, radicals who attacked abortion clinics in the 1980s and 90s, like assassin Paul Hill, "were sort of coldly rational" in their violent agenda, he added, "while Mr. Dear, whatever else he is, he's not a sober, rational mind. So he does seem different to me."

Organized acts of violence against abortion clinics, as part of a fringe faction of the pro-life movement, peaked and then fell in the 1980s and 90s, Shields explained in a Monday op-ed for the Washington Post, with an "exception" being the assassination of late-term abortionist Dr. George Tiller in 2009 which was probably an anomaly and not part of any violent trend.

"The shootings in Colorado Springs give us little reason to suspect that a renewed network of violent radicals is targeting abortion providers as they once did in the 1990s," he concluded.

Dear appeared in court Nov. 30, where he was told he would be charged with first degree murder.