CSI has been running in US for 14 seasons
So what makes a successful TV show? For screenwriter Carol Mendelsohn, the most important thing is an "emotional hook" that keeps curious viewers coming back.
In her case, they have been coming back for 14 years to the popular "CSI" TV
crime series, which has even survived the departure of its lead actor in its ninth season.
"All writers feel your project is like a child in a sense and you feel proud," the 61-year-old, who is also the show's executive producer, told AFP in an interview.
That "CSI: Crime Scene Investigation" has lasted 14 seasons is "such an accomplishment, but everybody that works in television knows it's not one person, not one department."
Seen by 63 million viewers around the world and deemed the most watched show on the planet six times, Mendelsohn said CSI's success is based in part on the fact that it "brings closure to victims' families."
"Because if there is a victim, there is always somebody who loved that victim," said the former Chicago lawyer who made a name for herself in the 1990s with her work on the drama series "Melrose Place."
"That closure is the emotional hook of the show."
She also linked the show's mass following to the fact that viewers are keen to learn new things.
"People want to learn stuff, to know things," she said. "And you can't watch an episode of 'CSI' without learning about something.
"Whether you're learning about science or you're learning that there are people that dress up like stuffed animals and that's the only way they can interact with each other and have sex," she added in a nod to a famous episode based on a real case.
But keeping things interesting all this time hasn't been easy and is a team effort.
'Science, crime and real logic'
"These shows are really hard to write because there's science, crime and real logic, plus, people don't believe it, but there is character," she said.
"It's very hard for one person to write it. So we use a writer's room."
There, writers and forensic experts who advise them share ideas and work on multiple screens where everyone can see what their counterparts are coming up with.
"I like to work collaboratively. You never take away from someone's creativity but it always helps someone to have other ideas," Mendelsohn said.
"It's a very challenging show and one person just can't figure it out."
Getting a little help from outside has also helped.
The end of the fifth season in 2005, directed by Quentin Tarantino, reached 35 million viewers, according to Nielsen ratings.
Since 2000, every episode of the CBS series has focused on a heinous crime that is subsequently investigated by a team of forensic scientists.
That team used to be led by Gil Grissom, played by William Petersen, who left in 2008 to pursue other projects.
His departure posed a big challenge "because Grissom was so synonymous with the show and they were big shoes to fill," Mendelsohn recalled.
What followed was an unsuccessful try to replace him with Laurence Fishburne as a rookie.
But Fishburne "was such an imposing physical presence and actor on the screen, nobody wanted to believe that he wasn't the head of the team," Mendelsohn said.
"It never quite worked."
So when "The Matrix" star left in 2011, the crew decided to create D.B. Russell's "family man" character, portrayed by Ted Danson, who breaks an unwritten rule on the show.
"We have this funny rule and it's true: we always say that if you have sex on 'CSI,' you die," Mendelsohn joked.
"It's probably very puritanical and very American," she added with a laugh.
"But people have great sex and they die. Or are accused of murder."
But "CSI" -- which is set in Las Vegas, and has spawned two spinoffs set in Miami and New York -- has been criticized by those who say it isn't true to life.
When the series first began, DNA test results would come in over the course of a commercial break, Mendelsohn said. That made no sense realistically at the time, but scientific advances have since been made.
"And forensic experts throughout the country said that's not true, it takes weeks and sometimes months to get results," she added. "But now the technology has caught up with our show."