As they announced charges that could send David and Louise Turpin to prison for life, prosecutors described a gruesome years-long nightmare of allegedly imprisoning, beating and psychologically tormenting their children.

The charges included: 12 counts of torture; 1 count of lewd act on a child against Mr Turpin; 7 counts of abuse of a dependent; 6 counts of child abuse; and 12 counts of false imprisonment. If convicted on all counts, they face 94 years to life in prison. While the Turpins have 13 children, prosecutors said they were not charging them for treatment of the youngest, a 2-year-old.

Both Turpins pleaded “not guilty” to all charges in a brief court appearance on Thursday.

Below are some of the allegations that Riverside District Attorney Mike Hestrin described at a press conference.

They were shackled with ropes and then chains

Initially, the children were bound with ropes — but when one escaped, the parents began to use chains and padlocks, Mr Hestrin said, often not freeing the children to use the bathroom.

Turpin family: 13 siblings who were held captive by their parents Show all 15 1 /15 Turpin family: 13 siblings who were held captive by their parents Turpin family: 13 siblings who were held captive by their parents David and Louise Turpin with their 13 children who were being held captive by their parents in the family home in Perris, California. Facebook Turpin family: 13 siblings who were held captive by their parents Riverside County District Attorney Mike Hestrin speaks during a press conference announcing charges against David Turpin and Louise Turpin in relation to their 13 malnourished children found chained in their home, in Riverside. The two parents were charged with multiple counts of Child abuse, torture, abuse of dependent adults and false imprisonment and could face close to 100 years to life in prison if convicted. EPA Turpin family: 13 siblings who were held captive by their parents The home of David Allen and Louise Anna Turpin, where some of their children were bound with chains and padlocks. Reuters Turpin family: 13 siblings who were held captive by their parents David Allen Turpin poses for a mugshot after being arrested. Riverside County Sheriffs Department via Getty Turpin family: 13 siblings who were held captive by their parents One of the captives, a 17-year-old girl, escaped over the weekend and notified the Riverside Sheriff’s Department. Facebook/David-Louise Turpin Turpin family: 13 siblings who were held captive by their parents Perris residents watch as media gather in front of Turpin family home. The Sheriff's deparmtent said "the parents were unable to immediately provide a logical reason why their children were restrained in that manner." AFP/Getty Turpin family: 13 siblings who were held captive by their parents The children were found in dark and foul-smelling surroundings and "The victims appeared to be malnourished and very dirty,” the department said. Facebook/David-Louise Turpin Turpin family: 13 siblings who were held captive by their parents Neighbours stand outside the home. Getty Turpin family: 13 siblings who were held captive by their parents Louise Anna Turpin poses for a mugshot after being arrested. Not all of their victims were children: of the 13 victims, seven were between the age of 18 and 29, according to the Sheriff's Department. Riverside County Sheriffs Department via Getty Turpin family: 13 siblings who were held captive by their parents David and Louise Turpin in 2015. Authorities arrested them on torture and child endangerment charges, setting bail at $9m (£6.5m) apiece. Facebook/David-Louise Turpin Turpin family: 13 siblings who were held captive by their parents David Turpin and Louise Turpin appear in court for their arraignment in Riverside Reuters Turpin family: 13 siblings who were held captive by their parents David Allen Turpin and his wife, Louise Anna Turpin celebrate a renewal of their wedding vows with Elvis impersonator Kent Ripley in Las Vegas in 2011 A Elvis Chapel via AP Turpin family: 13 siblings who were held captive by their parents David Allen Turpin appears in court for his arraignment in Riverside. Prosecutors filed 12 counts of torture, seven counts of dependent adult abuse, six counts of child abuse and 12 counts of false imprisonment against Turpin and his wife, Louise Anna Turpin. The Press-Enterprise via AP Turpin family: 13 siblings who were held captive by their parents Neighbour Liza Tozier, and her son, Avery Sanchez, 6, drop off his large "Teddy" as a gift for the children. AP Turpin family: 13 siblings who were held captive by their parents Louise Turpin appears in court for her arraignment in Riverside. Authorities say the abuse left the children malnourished, undersized and with cognitive impairments. Reuters

“These punishments would last for weeks or even months at a time,” he said.

When not chained to beds, he alleged, the children were locked away in separate rooms.

The parents set out toys and food they couldn't eat

Many of the children appeared to severely malnourished, with a 29-year-old weighing a mere 82 pounds, Mr Hestrin said.

But the parents would tempt them with food, including setting out pies that they could not eat.

Similarly, the house was strewn with toys still in their packaging despite evidence that the children were never allowed to play with toys, Mr Hestrin said.

David and Louise Turpin renew their wedding vows at Elvis Chapel in 2013

They were punished for washing their hands too much

One of the behaviours that could incur punishment — which could include beatings and strangulation in addition to being chained up — was when the children washed their hands above the wrists, which would lead the parents to accuse them “playing in the water,” Mr Hestrin said.

Hygiene for the children was poor, Mr Hestrin said, with the parents allowing them to shower no more than once a year.

They were deprived of medical care

It appeared that none of the children had ever been to a dentist, Mr Hestrin said, and that they hadn’t been taken to a doctor in more than four years.

*They had little knowledge of the outside world*

The family homeschooled its children and adhered to a schedule of sleeping all day and being active all night, Mr Hestrin said, helping to limit their contact with others.