AUGUSTA, Maine — The 18-year-old accused of slaying his parents in their Winthrop home over Halloween weekend told police he “killed his mom, dad and his dog,” according to the affidavit made public this week at the Capital Judicial Center.

Andrew Balcer is charged with two counts of murder in the deaths of Antonio and Alice Balcer, both 47.

Andrew Balcer was 17 when he allegedly stabbed his parents to death, so has been charged as a juvenile. Prosecutors have asked that he be tried as an adult.

The affidavit, dated Nov. 1, 2016, and sealed for 60 days on Nov. 17, said that Balcer called 911 at 1:42 a.m. Oct. 31. In response to questions from the dispatcher, he said there was “a lot of blood” and that “they (his parents) were beyond help and definitely dead,” the affidavit said.

His father was found lying on his back in the kitchen in a large pool of blood, according to the court document. A Ka-Bar-style knife was found stuck in the floor near his body and a handgun was found on the kitchen counter.

Balcer’s mother was found in a rear bedroom, according to the court document. She was face down and appeared to have been stabbed in the back.

Information on whether a dog’s body was found in the home was not included in the affidavit.

A possible motive for the slayings was not included in the affidavit.

Deputy Medical Examiner Dr. Clare Bryce found that Antonio Balcer had 13 stab wounds to his chest and torso. The autopsy on Alice Balcer had not been completed when the affidavit was filed. Efforts to determine the results of her autopsy were unsuccessful Thursday.

When police arrived about 1:54 a.m. on Halloween, Andrew Balcer came out of the house and surrendered without incident but asked them to make sure his brother was OK, according to the court document.

Balcer allegedly told police that his “brother is going to need a lot of counseling after this” and that “he is going to need financial assistance” because they were his only means of financial support.”

Since his arrest, Balcer has been held without bail at Long Creek Youth Development Center in South Portland.

A hearing to determine whether Balcer will be tried as a juvenile or an adult will not be set until after a psychological evaluation has been scheduled, according to defense attorney Walter McKee of Augusta.

If Balcer were to be convicted as a juvenile, he could be confined to Long Creek until his 21st birthday. If convicted as an adult, he would face between 25 years and life in prison.