A recent fan thread on Reddit confirms that we never physically see this unsub, despite their detailed history in “Criminal Minds.” User u/NieneDreamer noted a particular moment in Season 6 where we are introduced to a character named Ashley Seaver (Rachel Nichols), who is an FBI cadet brought on to the BAU team as a probationary member but has issues being drawn to her past because of her father, who turns out to be Charles Beauchamp, a.k.a. “The Redmond Ripper.” In the Season 6 episode “What Happens at Home,” we discover that Hotch and Rossi actually caught Beauchamp when Seaver was a child and Hotch was a relatively new agent on the team.
Beauchamp was incredibly protective over his daughter even though he killed 25 women in a seemingly brutal fashion. The episode shows him trying to provide Seaver with the best life possible, attempting to avoid homicidal urges, and even referencing the day Hotch and Rossi catching him as the best day of his life. Not often are unsubs shown as regretful or admitting that they acted out of urges. It is also mentioned that Beauchamp still writes to Seaver, but we never physically see him doing so.
Either way, u/dubscurry30 noted that the arrest of Beauchamp had to have occurred sometime before 1997, given Seaver’s timeline and Rossi’s 10-year retirement before rejoining in Season 3. The Redmond Ripper mostly serves as a useful development of Seaver’s character, as user u/IisforIda mentioned. Many crime shows have shown us the two-way street of children with psychotic parents — they either become the killer or the person who catches them.