The documentary series “Secret Lives of Women” (9 p.m., Eastern, WE) looks at one of the more peculiar phenomena of recent history: women who fall in love with men behind bars. “Secret” uses recent news footage to recall the short, violent escapade of a so-called “Bonnie and Clyde” couple who shot their way out of prison. It turns out the woman had been a rather meek and submissive nurse before taking up with a convicted criminal.

The hour-long expose shows that while these women betray an extreme predilection for very bad boys, they come from all races and income and education levels. Two women write extensively about the men – now their husbands – who are still behind bars. One woman is a black American political activist, another a white Canadian novelist. Both remain devoted to their men and defend their decisions.

Not all of the women here are so well spoken or in charge of their lives. Some seem naive and desperate, to say the least. One male prison guard says he can’t believe the number of love letters and other “fan” mail sent to convicted serial killers. Most of the women profiled here found their men through prison-outreach pen-pal programs or on the Internet.

“Secret” is rather long on odd anecdotes and short on theorizing. One woman does have her ideas about the romantic attraction of the incarcerated. She thinks the modern world has forgotten about old-fashioned romance. She cites books and stories going as far back as Shakespeare when courtship and seduction faced impediments both natural and manmade. And since there is nothing more difficult and fraught with frustration than courting a man behind bars, this may be the most “romantic” love of all. Or at least that’s how the theory goes.

¢ Filmmakers look at the development of a human baby from a cluster of cells to a newborn in the two-hour documentary “In the Womb” (8 p.m., National Geographic).

¢ Twenty years after the documentary “Little People,” director Jan Krawitz revisits her subjects — individuals affected by dwarfism — in the 2005 film “Big Enough” on “POV” (9 p.m., PBS, check local listings).

Tonight’s other highlights

¢ Ethical questions complicate a liver donation on “House” (7 p.m., Fox).

¢ On back-to-back episodes of “Veronica Mars” (UPN), a chance meeting with Troy (7 p.m.), Steve Guttenberg guest stars (8 p.m.).

¢ On back-to-back episodes of “Gilmore Girls” (WB), Sherilyn Fenn guest stars as Luke’s ex (7 p.m.), Luke’s secret revealed (8 p.m.).

¢ Auditions continue on “Last Comic Standing” (8 p.m., NBC).

¢ Smuggled remains may explain a young patient’s cancer on “Bones” (8 p.m., Fox).

¢ Scheduled on “48 Hours Mystery” (9 p.m., CBS): the murder of a bookie’s wife.

¢ Exotic dancers shake their last on “Law & Order: Special Victims Unit” (9 p.m., NBC).

¢ A teacher sues overinvolved parents for harassment on “Boston Legal” (9 p.m., ABC).