One team killer who was in it for the thrill was Leonard Lake.  When he was arrested in 1985 for illegal possession of a weapon, he swallowed a cyanide capsule.  The police were mystified by his rather extreme reaction, but then they found out his secrets. He owned a cinderblock bunker outside Sacramento, California, where he and his partner, Charles Ng, had taken numerous people to torture and kill.  It's estimated they may have had as many as 25 victims, both male and female.  Some had responded to classified ads or the promise of a job, and a few of them were even related to their killers.  Lake took photographs and videotapes of his attempts at sexual slavery, and he wore clothing that suggested some sort of cult activity.
Ng was 15 years younger and had gotten his criminal start with shoplifting and theft.  He'd been arrested while in the marines, but had escaped.  Seeing one of Lake's ads for a mercenary soldier, he went looking for the man and they soon became a team.  He may not have realized that Lake actually wanted a killing partner, but there's no doubt that he eagerly participated in the spree. Lake left a diary and videotapes behind that provided graphic images of sexual torture, murder, and cremation, and these tapes included Ng.  After strangling or shooting a victim, they dismembered them with a power saw and burned them in metal drums.  Any bones were pulverized and buried in bags.  Later, police found 45 pounds of bone fragments and teeth. Although Lake had eluded justice by causing his own death, Ng was extradited from Canada and put on trial.  He caused numerous delays, firing one lawyer after another, and insisted that he was both an unwilling accomplice and a changed man.  His criminal proceedings were the most expensive in U.S. history.  Finally he was convicted by a savvy and disgusted jury in the murders of six men, three women, and two babies, and given the death sentence.  He quickly appealed this sentence, based on its cruelty, and will no doubt spend even more of taxpayers' money before it's over.