McCollum's law-enforcement career began in 1982 at the Rape Crisis Center at Grady Memorial Hospital in Atlanta, Georgia.

[7][8] CCIRI has since worked with 27 colleges and universities, more than 8,000 students and 600 experts, who have volunteered their time and talents to solve cold cases.

[9] a nationwide volunteer network made up of 27 colleges and universities, 600 forensic professionals and 5,000 students that assist victims' families and law enforcement by working on unsolved homicides, missing persons and kidnapping cases.

[2] She is a contributing writer for CRIME online,[14] a crime-fighting website founded by Nancy Grace, television personality and former prosecutor.

McCollum co-authored, with cold-case expert Betsy Ramsey, the book Cold Case: Pathways to Justice, released in 2010 by Pearson Learning Solutions.