Robert Dear vandalized Planned Parenthood clinic decades ago in South Carolina: ex-wife
Robert Dear at his arraignment (NBC News)

An ex-wife of Robert Lewis Dear, the man accused of shooting dead three people and wounding nine at a Planned Parenthood center in Colorado Springs, told NBC News on Tuesday that he once put glue in locks at another of the agency's clinics.

Dear, 57, was told at a court appearance on Monday that he faces first-degree murder charges.

But formal charges have not yet been filed and authorities have declined to discuss publicly the possible motive for the attack at the Colorado Springs clinic, which carries out abortions and provided other health services.

The shooting has led to a debate over whether the anti-abortion movement's rhetoric might have played a role in inspiring the attack.

Dear's ex-wife Barbara Mescher Michaux, who resides in South Carolina where Dear once lived, told NBC News that more than 20 years ago he put glue in the locks of a Planned Parenthood clinic near where the couple was then living. They were married from 1985 to 1993, according to NBC News.

An attorney for Dear could not be reached for comment late on Tuesday.

Planned Parenthood has said reports that Dear told investigators "no more baby parts" after his arrest on Friday showed he was acting on an anti-abortion agenda. Reuters could not independently confirm that reported comment.

The shooting at the Planned Parenthood clinic in Colorado's second-largest city left a police officer and two civilians dead, in the first deadly attack on a U.S. abortion provider in six years.

Dear, in his first court hearing, appeared before a judge on Monday by video link from jail.

The judge told Dear that if convicted of first-degree murder he faces a minimum sentence of life without parole or a maximum of death. Documents in the investigation of the shooting were ordered sealed by the court.

Watch this video report posted online by NBC News:

(Reporting by Alex Dobuzinskis in Los Angeles)