Prosecutors are planning on seeking the death penalty for the man accused of killing 17 people at Marjory Stoneman Douglas High School last month, according to court filings.

Nikolas Cruz, who was arrested after the shooting in Parkland, Florida has been charged with 17 counts of premeditated murder in the first degree, and 17 counts of attempted murder in the first degree.

Prosecutors in the case listed several aggravating factors that they say contributed to the decision to seek the death penalty, including that Mr Cruz “knowingly created a great risk of death to many persons”. The filling continues to say his crimes were “especially heinous, atrocious or cruel”, and “committed in a cold, calculated, and premeditated manner”.

The filing follows after Mr Cruz’s attorneys signalled that their client was willing to plead guilty to avoid the death penalty.

Prosecutor also noted that they would like restrictions if the defence decides to try and introduce proof that their client mentally ill or suffering from some sort of mental condition.

That includes a deadline for filings like those, which could come into play since it is widely reported that Mr Cruz has battled with mental illness and depression in the past, especially following the November death of his adoptive mother.

Florida shooting – in pictures Show all 10 1 /10 Florida shooting – in pictures Florida shooting – in pictures Police arrest a suspect in connection with the shooting at the Marjory Stoneman Douglas High School in Parkland, Florida Reuters Florida shooting – in pictures Parents wait for news after reports of a shooting at Marjory Stoneman Douglas High School in Parkland, Florida AP Florida shooting – in pictures Anxious family members wait for news of students AP Photo/Wilfredo Lee Florida shooting – in pictures Students being evacuated from the school AP Florida shooting – in pictures Students being evacuated from the school Getty Florida shooting – in pictures People gather waiting for word from students AP Florida shooting – in pictures Parents waiting for news on their children AP Florida shooting – in pictures People gather at a hotel where students were taken after the shooting Getty Florida shooting – in pictures Florida Governor Rick Scott speaks to the media as he visits Marjory Stoneman Douglas High School following the shooting AFP/Getty Florida shooting – in pictures Dr. Igor Nichiporenko, Medical Director Trauma, left, and Dr. Evan Boyer, Medical Director, Emergency Services, speak about treating victims and the suspect at a press conference outside Broward Health North hospital AP

Mr Cruz has confessed to authorities that he was the gunman who opened, according to a probable cause affidavit that was released soon after his arrest.

The defendant was arrested shortly after the shooting at the high school, which is the worst high school shooting in US history. He had exited the school he assaulted alongside students, and had wandered away from the scene before getting picked up by a police officer who saw him in a residential neighbourhood.