(Court TV) — Videotapes taken from the home of convicted killer David Westerfield indicated he secretely filmed women living in his San Diego neighborhood, according to newly released court documents.

Westerfield, who was sentenced to death earlier this month, was a "Peeping Tom," who had a history of spying on his neighbors before he kidnapped and murdered 7-year-old Danielle van Dam, according to prosecutors. The allegations are part of hundreds of pages of legal motions unsealed this week.

Of the three 8mm tapes taken from his home, one allegedly shows a female neighbor, filmed through her bathroom window, drying off after a shower. Another shows a woman inside her home through a window, according to the documents.

A third shows Westerfield having sex with a woman whom the documents say "did not appear to know she was being filmed."

Prosecutors argued in court papers that the videotapes, along with several sets of binoculars and a bent window screen in his bathroom, showed how Westerfield "gained sufficient knowledge of the Van Dam family and residence to enable him to commit this crime without getting caught."

The second-grader was stolen from her bed Feb. 2, 2002, while her two brothers and father slept down the hall. Her badly decomposed body was found three weeks later by a roadside.

The judge in Westerfield's trial ruled the jury couldn't hear about the tapes because they were irrelevant and too prejudicial.

— The Associated Press contributed to this report.